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How to graph data for your science fair project

Posted by on April 8, 2012

Once you have your data, you will need to present it to your teacher and science fair judges. In a science publication, you would choose between a table and a graph, but for the science fair project it is acceptable, and even encouraged, to showcase the data in both forms. If you have to pick (teacher’s rules), then a graph (picture) is better than a table (numbers), EXCEPT that most scientists really, really like numbers – so we are happy to see the table too.

Type of graphs: Your first choice is to determine which type of graph would best communicate your findings. Your basic choices are bar graph, line graph, pie chart, or scatter plot.

BAR GRAPH – This is the most common type for science fair projects. You may select a bar graph when your independent variable is qualitative (categories) or quantitative (numbers). It is generally better to group the data by TREATMENT instead of TRIAL # because it allows a better comparison of variation within the treatment. This might not be intuitive if you collected by trial, but it is the better way to showcase your results.

An example of a bar graph

Look closely and make sure your bar graph has all the highlighted parts:

Independent variable may be qualitative or quantitative

LINE GRAPH – This is the second most common, but frequently used incorrectly, so be careful here. You should only select a line graph if your independent variable is quantitative (numbers) and you hypothesized that the changes in the independent variable would result in changes in the dependent one. For example, line graphs are great for showing changes in the dependent variable over time or distance along a transect.

An example of a line graph

Again double check the axes:

Independent variable MUST be quantitative

PIE CHART – Pie charts are good for projects that have qualitative independent variables and have generated data that can be expressed as percentages of the total. For example, if your data were counts (i.e. the number of times something happened), then this might be your best choice to compare different treatments.

An example of a pie chart

SCATTER PLOT – If the purpose is to see if the variables are related (common in environmental projects), but there was not a clear choice for independent and dependent variables (for example wind speed and water temperature), then a scatter plot would be your best choice. This option typically requires much more data than the others to observe a trend.

Scatter plots are also called X-Y plots

Scientists do not label graphs with a title, but if your teacher asks for one — make sure that is there too.

71 Responses to How to graph data for your science fair project

  1. jeffery

    this is a nice thing you are doing

  2. Sharee

    Excellent information, great page theme, continue the great work

  3. carolina

    i really need help on my data

    • Dr. Maille Lyons

      What do you need, that you didn’t find here?

      First, think about which variable did you change? – that will be your INDEPENDENT variable and it will go on the x-axis (horizontal one). Now determine your DEPENDENT variable – it is the thing that you actually measured or counted. These data will go on the y-axis (vertical one).

      If your independent variable is quantitative (numbers) then you could do a LINE graph or a BAR graph, but if your independent variable is qualitative (categories like colors, or male vs. female, or high-med-low) then you should be making a bar graph.

      Hope that helps, if not – ask a more specific question – what help do you need?

  4. isabella

    I am confused. I am in 6th grade and I did my project on my question can I grow stalactites in a manipulated environment. I did two experiments. One in the house with a set temp of 76 degrees, and the other in the garage at random temps. How would I do a graph? They both grew but differently. I am not sure what kind of graph to do, thank you

    • Dr. Maille Lyons

      OK – let’s take a look at what you did:

      1 experiment with 2 conditions: a. constant temperature condition and b. variable temperature condition

      How did you measure growth?
      If you only measured growth one time at the end, then you could do a bar graph showing the total growth attained. One bar for each condition – bigger bar wins!

      If you measured growth several times over the course of the time you let them grow, then you could do a line graph showing growth (y-axis) over time (x-axis). One line for each condition.

      You may want to re-phrase your question: What is the effect of temperature variation on stalactite growth?

      Hope that helps!

  5. Sydney

    I don’t know how to graph my data. I did which product affects the decaying of apple slices the most. I used Epsom salt, salt, and baking soda. The salt slowed down the decaying the most, and the baking soda sped it up the most. How do I put this into a graph????

    • Dr. Maille Lyons

      OK – what did you actually measure? In other words, how did you get to the conclusion that the salt slowed down the decaying the most?

      Was it time (how long it took each one to decay?)
      Was it weight loss? or Percent weight loss?
      Was it percent color change?

      You will most likely be doing a BAR GRAPH- with each treatment: Epsom salt, salt, and baking soda on the x-axis and whatever you measured on the y-axis

      If you did a control (no treatment) – you can calculate the percent change from the control value

  6. Becky McKenzie

    I did an experiment melting M&M’s, trying to see if certain colors melt faster than others. I am trying to find a graph to show my results. I have not made a graph on the computer before. Please advise me as to website that would be best. Thanks.

  7. Martha

    I am doing the experiment how sodas affect tooth decay. Choose 4 sodas placed teeth in each measuring 600ml watching changes to each tooth over a 5 day period to observe which soda caused the quickest decay. How do i place the information on a graph?
    Thank you.

    • Dr. Maille Lyons

      How are you measuring “decay” – visually or will you weigh them… or ?

      If you have a quantitative dependent (time, weight, size, etc.) then that will go on your y-axis with type of soda on your x-axis.

  8. Sydney Juranty

    Thanks so much!

  9. Christopher Gallagher

    I am doing my science fair project on Wind using a homemade anemometer. I will be testing the wind every morning for 7 days and then compare the wind activity for the same seven days last year. How do set up a graph in excel? I am so confused and dont know how to set the formulas up-please help!

    • Dr. Maille Lyons

      First, what was your question?

      Based on what you have provided, it sounds like you want to compare this year’s 7 days to last year’s 7 days. I would recommend a line graph with day (1-7) on the x-axis and wind speed on the y-axis. Put one set of data (e.g. this year) in one color and the other set (e.g. last year) in another color. You will be able to see which line was “higher” (i.e. more windy) and which line was “more variable” and hopefully that will answer whatever question you selected.

      You can use excel to make a graph, but it will be hard for me to explain how if you aren’t familiar with excel. I generally recommend this website:

      (cut and paste into your browser; or Google “Create a Graph”)

  10. sheila scott

    Hello, I am doing my 6th grade Science Fair Project on Whether Pop Cans will sink or float. I used Coke, Diet Coke, Coke Zero, Caffeine Free Diet Coke, and Caffeine Free Coke Zero. They all floated except for the Coke. How would I do a Graph or Chart for this.

    Thank you for you help
    Sheila Scott

    • Dr. Maille Lyons

      How many cans per type of soda did you do? Were the results all the same? You should probably just do a table with Type of Soda across the top and sink and float down the side: then fill it in with yes or no.

      • Kamden

        I’m doing this same type of project also. I wanted to note the sugar weight and how that effected floating and sinking of regular sodas versus diet sodas (containing small amounts of aspertame). I also weighed the cans on a gram scale (they were all a little different) Is there any way to make an actual graph to display on my science fair board? Thanks!

        • Dr. Maille Lyons

          If the only thing that you “measured” was yes or no regarding the floating … then no, not really. If you measured the time it took to for the can to sink or float then you could put that on the y-axis (bar graph)

  11. Darlene Couch

    My daughter is doing a science fair project on which soda stains teeth the most. She is using visual comparisons. How can she graph and chart this

    • Dr. Maille Lyons

      Generally, you can’t graph qualitative variables like which one stains the most unless you can come up with some sort of a rating scale. For example if she sets up a sequence from “no staining = 0″ to “light staining = 1″ to “moderate staining = 2″ etc. up to heavy staining with whatever number you are on… then she could make a bar graph with soda on the x-axis and staining on the y-axis. You may need to establish the rating scale using something like time (so “light staining = 1″ would be the equivalent to soaking for 1 (hour or day or week depending on the scale you are making)). You might need a rating scale for each soda, for example, you shouldn’t use a staining scale made with a cola to evaluate an orange soda.

      Alternatively she might be able to re-phrase the question looking at how long (time is a quantitative variable) does it take to get to a certain level of staining and then compare “time” as a proxy for “stains the most”.

  12. Luly Fundies

    Please help me, i think i should use a bar graph and have different colors for each trial, because i am finding the speed of waves through three trial. (by waves i mean waves from the eleectromagnetic spectrum)

    • Dr. Maille Lyons

      I need a bit more information… Sounds like you could use a bar graph for that type of data. You would have speed on the y-axis and what ever was different in each trial on the x-axis

  13. Jessie

    My daughter is in 3rd grade and has to show a graph or table but I have no idea how to help her with this… Her project was sucking an egg through a bottle and all three times the egg went in… How would you graph it or make a table with that information?????

    • Dr. Maille Lyons

      If she measured the time it took for the egg to go in, she could do a bar graph of treatment (x-axis; i.e. different conditions under which she tested the egg drop) vs. time (y-axis). If she didn’t measure the time but noted which conditions made the egg go in faster, she could make a table and rank them slow, medium, fast.

  14. Erli

    Hello , my daughter is doing a science project : color changing carnation , but we do not know how to make a graph , we use a food coloring in blue , 4 tubes , with 4 carnation , de first tube no colorant so no change , the second tube 10 drops , the third 20 drops and the fourth 39 drops of blue , the flowers in tube 2,3,4 changed blue , the fourth was the darker , how we can do ? Please and thanks so much !!!!! We do not know what to put in x axis and in y axis

    • Dr. Maille Lyons

      The x-axis (horizontal) would be the number of drops, the y-axis would be something you measured. For example the time it took to first see color, or some measure of “how blue” each flower was. If you only have a yes/no as to color, then you can not make a graph. I would suggest making a table and including photographs to show the differences between the color in each flower as a function of how much food coloring was in the tube.

  15. Erli

    Thanks so much !!!!! We measured the time , for example ; we checked every two hours , and we saw changes in color , until 10 hours that was the darkest point . In the x axis can we put tube a ,tube b , tube c and tube d and in parenthesis 0 drops , 10 drops , 20 drops and 30 drops ?. The problem is the y axis , we do not know how to arrange it …. We can use the hours , for example 0,2,4,6,8 and 10 , but what we create the bars ? Thanks !!!!!

    • Dr. Maille Lyons

      You could make a TABLE with each Column being the Tube and each Row being the Time in two hour increments; the boxes would then be filled with words describing the color changes in each tube – so marking when the first signs of color appeared and then which ones got darker and when.

      For a BAR GRAPH, you would set up the x-axis as you described above and then use the TIME TO FIRST SIGN OF COLOR CHANGE (should be a single time point) or you could use TIME TO DARKEST COLOR CHANGE (if they didn’t all become the same color by 10 hours)

  16. Marguerite

    We need to graph 20 trials in which there was only one response per trial: Yes or No. Can we do a line graph for this and how would it be done?


    • Dr. Maille Lyons

      No – sorry, you can’t do a line graph with that type of data. At best you can do a bar graph to show what % of the 20 trials were yes, but if you don’t have a control group, then you would only have 1 bar. Try a pie chart with the % of yes vs. no

  17. Kery

    My daughter did a project on Which Stemmed Flower Lasts The Longest In water after picked. We did a rose, carnation and an amaryllis. We did two experiments, one set of flowers in one cup of water and one set with 1/2 cup of water for two weeks. How would you recommend that we graph this and which graph would be good to use?

    • Dr. Maille Lyons

      I will assume you measured “time” for your dependent variable? Then you would make a bar graph with flower type on the x-axis and time on the y-axis. I am not clear why you did one cup of water vs. 1/2 cup of water. Were there differences? If yes, make two graphs (one for each) but if not, average the results (or present two bars per flower type) on the bar graph.

  18. James

    Hello, my name is James and I am in 3rd grade. I am doing which method makes most tender beef. I used soy sauce, baking soda, meat tenderizer hammer and a control that did not have anything done to it. My dad cooked the meat. We gave a piece of each one to 5 of his friends. They decided which one was most tender down to the least tender. The baking soda was most tender. The control was least tender. They had different ranks for least to most tender. What is the best graph to use for this data? Thank you.

    3rd grade

    • Dr. Maille Lyons

      Great project! You could do a bar graph with “treatment” on the x-axis (control, soy sauce, meat tend., and hammer) and then the “average” rank on the y-axis. You would need to convert the “ranks” into numbers, just set a scale from least (1) to most (5?) and then average the numbers. I would also include a data table showing the each of the 5 friends ranks for each of the 5 treatments (set up a 5 by 5 table).

  19. Echo

    I am doing a science fair project to see if lemons or potatoes will keep a lightbulb lit the longest. I put ‘Time the lightbulb stayed lit(min)’ as my dependent variable and lemons and potatoes as my independent variables. (I.e. in the bar graph you made, coffee and water would be substituted for lemons and potatoes.) Is this correct? The main problem I’m having with this is that I’m not sure what I should put as their title, for example, where you put treatment. Can you please help me? Thanks!

    • Dr. Maille Lyons

      “Treatment” still works for you, it is just a generic term for “things that varied in my experiment”; Alternatively you could use “Battery” or “Organic Battery”. Make sure the “Batteries” are on the x-axis and time (min) is on the y-axis.

      • KZ

        I am doing a science fair project on how to make a potato powered light bulb. I’m lost on trying to make a graph/table. Can you help me please

        • Dr. Maille Lyons

          To make a graph, you need to collect data… so are you testing different types of potatoes? or brightness of light? or length of time light works? If the question is just “can I make this work” and the answer is “yes or no” then there is no graph to be made. You can try making the potato powered light bulb and then changing one aspect of it and seeing if you can make it “better” – then at least you could make a bar graph with the thing you changed (=independent variable) and the measure difference (=dependent variable).

          • KZ

            How about if I used a russet potato and a sweet potato? What can I measure between the two?

          • Dr. Maille Lyons

            That is the key … what will you measure? You can try measuring brightness (you would need a light meter) or time (see if one lasts longer than the other – but that could be a long time to wait; and they would need to be the same size) or something else. You want more than a yes/no answer of did it work or not otherwise it is still just a demonstration and not an experiment.

  20. Alexis

    If I have 10 trials, and in each trial I mark yes or no that my bug tried to climb the wall of the maze, and I want to show change over time, how could I show that on a line graph?

    More info on my assignment:
    First three trials were baseline.
    The next eight tracked whether or not wall climbing happened while my intervention was in placed.

    So, I need to show the Yeses go down over the course of ten trials and the No’s go up over the course of the same ten trials. I want to show it on the same line graph for comparison, but I can’t figure out how to show it .

    • Dr. Maille Lyons

      OK – so there is no line graph in your future… sorry, you don’t have the correct type of data.

      And I can’t see 10 trials based on the info you have provided. You have 3 trials for a control and 8 trials for an experiment (I am assuming your “intervention” was the same for each of the 8 trials).

      You can do a bar graph showing what percentage of times “wall climbing” occurred by calculating the number of “yes” for the control (0 out of 3; or 3 out of 3; or # out of 3) and compare that to the percentage of times for the intervention (# out of 8).

      If you are trying to show “learning” – that perhaps the bug learned to climb (or not climb) the wall, then make a table of the 8 trials in the order that they were done, perhaps it would show a pattern if, for example you had data like: yes, yes, yes, yes, yes, no, no, no – would suggest the bug “learned” not to climb as compared to if your data looks like: yes, yes, yes, no, yes, no, no, yes – Do you see the difference?

      Did you always you the same bug?

  21. cathy

    I am creating egg geodes for my science project. I have several solids such as alum, sea salt, Epson salt, and sugar. I’m not sure about my question or my graph. Please help

    • Dr. Maille Lyons

      That’s a great idea – but it is not an experiment. You need to vary something and measure a difference in the outcome of something. So you could ask: Which solid creates the biggest geode? (Then vary the solids and measure the size of the crystals in the geode). Or you could ask Which solid creates an egg geode the fastest? (Then vary the solids and measure the time to complete formation).

  22. kaila davis

    Hello, for my sience fair project I am doing witch beverage stains your teeth the most. To test that am going to use eggs, i am going to put the egg in one type on drink, then I am going to let it sit for one day, the I am going to place a whitening strip on the egg for one day then I am going to compair the results. I repeating this procedure with different types of drinks. I need help with graphing, could you help me as soon as possible!?!

    • Dr. Maille Lyons

      Unfortunately, you will not be able to graph anything because you are not actually measuring a number and graphs require numbers – i.e. your dependent variable is qualitative (“darkest color”) not quantitative (has to have a number associated with the measurement).

      You will be able to rank them: first, second, third, etc. according to their ability to stain the “teeth” (i.e. eggs).

      Take lots of photos and use the photos to show your results and the rankings. Also – you should soak THREE eggs for each type of drink you test for proper repliction.


  23. kaila davis

    Like what graph should I do and what should be in my graph.

    • Dr. Maille Lyons

      Sorry – You can NOT make a graph because you do NOT have any numbers to put on the y-axis. Even though the x-axis can have numbers or categories (i.e. soda types) the y-axis needs a real number.

  24. kaila davis

    Could i do a table, if I can what should I put in it?

    • Dr. Maille Lyons

      If you recorded observations for each time then you could do a table with the type of soda for each row, and the day for each column and whatever observations you made in the box.

  25. Jordan Smith

    I have a quick question as to how I should graph my data. My science fair project is to examine how 3 different type of gymshoes effects how one completes a crossingover using a basketball. So, basically I want to ind out will each different shoe yield different results of a crossover(skill in basketball)

    Thank you

    • Dr. Maille Lyons

      What are you actually measuring?

      If it’s “time” then make a bar graph with the type of shoe on the x-axis and time on the y-axis.

      If it’s “success” – i.e. yes/no was the skill completed correctly then the y-axis will be the percentage completed (# of successes divided by total number of attempts).

      Regardless: You should do at least 10 trials (ideally 10 different people completing the skill one time, each wearing the shoe being tested, etc.). The problem with using the same person 10 times is that – in theory – they should get better with practice so the number of successes will be potentially related to practice (not the shoe). So if you are testing at least three types of shoes then you will need about 30 people randomly distributed into three groups (i.e. don’t put all the basketball players in one group). If you can only find 10 people and you want them to each try the skill in each type of shoe… then randomize the order in which they test the shoes (i.e. do not always test running shoe first, then court shoe second, then high-top third- because you will run into the “practice” problem again).

      Hope that helps!

      • Jordan Smith

        Thank so you so very for responding and yes that helped. I will be measuring success so I will use the bar graph but can you give me a example of what should be represented in my bar graph? Should I list every shoe at the x-axis (bottom) – as you suggested that the # of success divided by the total attempts should go list on the y-axis(along the side) but what does it look like in numbers? By the way I am a 8th grader :)
        Thanks again!!!

  26. Jennifer

    Hello, I’m doing a science project on How do different sodas effect the meats we eat. And I’m not sure how to do a graph or data chart?

  27. Nata

    Hi I’m helping 4th grader record data. For chicken breast and sprite coke water project
    Really need some assistance on how to graph??

  28. Nata

    Measure chicken breast with coke , sprite and water.
    Effects of brand of soda on raw meat
    Will not soak up

  29. Nata

    Thanks for your help!

  30. Lynn

    This website is wonderful! Thanks so much for helping the parents and kids with our science expo projects. My daughter is doing an experiment on: Do bananas ripen faster in the light or dark? She did three experiments and took pictures at the beginning of the experiment and then pictures at the end (day seven). Is there a way she can use a graph to display her findings, or is it ok to just use pictures?

    • Dr. Maille Lyons

      In order to make a graph, you need numbers.

      If you can estimate % browning from the photos you could use that for a graph. One way to do this is to make a grid using a transparency. Place the grid (smallest squares that are practical) over the photo. Count the total number of squares each banana fills (let’s say you get lucky and it’s exactly 100). Count the total number of squares that have some brown (let’s say 50 of the 100 are at least partially brown). Then for that treatment (light or dark) you would have an estimate of the % browning (or % yellow if that was the observation for “ripening” – whatever she was monitoring) for each treatment; in this case you might conclude bananas in the dark ripened 50% more than bananas in the light (assuming when you do same thing for other bananas you get no browning; etc.).

      You could then make a bar graph with treatment on x-axis and status (i.e. % ripe or % brown etc.) on y-axis

  31. Lynn


  32. Reece Meyer

    I am doing the science fair for school and for my project I need to make a table for collecting data, NOT A GRAPH. Can you help me make one or find a helpful website so I can make one online and print one off? THanks!!

    • Dr. Maille Lyons

      Data tables can be made in any spread sheet program (e.g. Excel). A table is just a set of columns and rows that you can organize your data in. You could even make a table with a rule and pencil.

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