Group projects are easy to mark and hard to share out. This calculator takes the grade your project earned and splits it between members using contribution percentages, so everyone can see their share before the grade goes in.
It is for the moment at the end of a group assignment when one person wrote three of the five sections and somebody else turned up for the last two meetings. You put in the numbers, it puts them in a table, and the argument gets shorter.
Honest detail: the contribution boxes have to add up to 100%, and the tool is picky about it. Ninety nine percent fails. The small print on that is below.
Enter the total project grade and each member’s contribution percentage. This calculator splits the grade fairly based on how much each person contributed. Contribution percentages should add up to 100%.
How the split works
Three inputs drive everything. Total Project Grade is the mark the whole project earned, between 0 and 100. Number of Group Members accepts 2 to 10 and starts at 3, and every time you change it the contribution fields are rebuilt empty, so fill them in last. Each member then gets a box for their share, also 0 to 100.
The maths is one line: member’s grade = total grade multiplied by their contribution, divided by 100. Every row in the result table is that sum, shown to one decimal place, alongside the contribution you entered. Underneath, the tool repeats the total so you can check the column adds back up to the project mark.
Validation is strict and it is strict on purpose. Anything outside 0 to 100 is rejected, and the contributions must land within half a percent of 100. So 33/33/33 is refused with a current total of 99.0%, while 33.4/33.3/33.3 goes through at 100.0%.
Reset clears the total, puts the member count back to 3 and rebuilds the contribution boxes from scratch. Useful when you want to run the same project mark through two different splits to see who ends up ahead, which is a conversation a lot of groups have more than once.
A worked example
The project came back as 90% and three of you wrote it. Member 1 did the research and half the writing (50%), Member 2 did the analysis (30%), Member 3 made the slides and presented (20%). The table returns 45.0%, 27.0% and 18.0%, which add up to 90.0%, the project mark itself. That is the test worth running on any split you are offered: the shares should add back to the total, not to 100.
Four people who genuinely shared it equally on a project marked 78% gets 25% each, so 19.5% apiece. Nothing dramatic happens, and that is the point of entering even numbers rather than pretending there was a hierarchy. Now try 33/33/33 on three members: the tool refuses it and shows 99.0% as the current total. Nudge the last box to 34 and it accepts.
When this is the wrong tool
These are shares of the project mark, not final course grades, and the difference matters. If the project is worth 30% of the course and your split gives you 45%, that is 13.5 percentage points of your final mark, not 45. Do that conversion yourself, or use your course syllabus weights.
Plenty of teachers give a group one mark for everyone regardless of who did what, in which case an even split is the honest entry and this calculator just confirms the arithmetic. Ask before you assume, because a beautifully split grade that your instructor never intended to split is worse than one flat grade. And agree the percentages with the group while the work is still fresh, not the night before submission, when nobody can remember who did the literature review.
Other tools
- Hemocytometer cell count — the lab half of a project where the raw numbers still need counting
- Drop the lowest homework grade — for when one bad mark should not count at all
- Honours GPA requirement — what the grade actually has to be by the end
Frequently asked questions
What if my percentages do not add up to 100?
You get an error with the total it found, and nothing is calculated. It accepts anything within half a percent of 100, so 99.6% passes and 99% does not. Fix the numbers rather than rounding them off, since a lazy 33/33/33 is the common trap here.
Can I use it for two people?
Yes, set the member count to 2. A 50/50 split is the usual answer, but 60/40 is fine when one person clearly carried more of it. The table works the same way for pairs as it does for six people.
What if everyone contributed the same?
Enter equal percentages, 25% each for four members, and the tool hands each of them an identical share of the project mark. There is no rule saying you have to find differences that were not there.
Can somebody be given zero?
0% is accepted by the calculator and earns that member 0% of the project grade. Whether your instructor will honour it is another question, and free-rider policies vary between departments, so check before you submit something that assigns a classmate nothing.
Does this set my final course grade?
No, it only splits the project mark. Your course grade depends on how much that project was worth alongside everything else, so multiply through yourself if you need the real number. This is a guideline for a fair split, not a promise about your transcript.