Random Group Generator
This random group generator plans fair group splits for any class size. Enter the number of students and your target group size to get the number of groups, how many students are left over, and a suggested even redistribution so no group is stuck as the odd one out. It plans the split structure — assign the actual names by drawing lots, dealing cards, or shuffling your roster.
Ideal members per group; the plan evens out remainders.
Number of groups
7
- Number of groups
- 7
- Target group size
- 4
- Leftover studentsDivides evenly — no leftovers.
- 0
How it was calculated
- Raw split: 28 ÷ 4 = 7 full groups with 0 left over.
- Even split: all 7 groups of 4 — perfectly even.
- Assign membership randomly: shuffle the roster, then deal students round-robin into groups 1–7.
How it works
Full groups = floor(students ÷ target size) and the remainder is students mod target size — e.g. 30 ÷ 4 gives 7 full groups with 2 left over.
Total groups = full groups + 1 when there is a remainder, otherwise just the full groups.
The even split divides students across that many groups so sizes differ by at most one: base = floor(students ÷ groups), with (students − base × groups) groups getting one extra member.
Membership itself is not computed here — shuffle names and deal them round-robin into the planned group slots for a truly random assignment.
Worked examples
28 students, groups of 4
28 ÷ 4 = 7 full groups, remainder 0. Total: 7 groups. Even split: all 7 groups of 4 — perfectly even, no redistribution needed.
30 students, groups of 4
30 ÷ 4 = 7 full groups with 2 left over → 8 groups total. Even split: base = floor(30/8) = 3, bigger = 30 − 24 = 6 → six groups of 4 and two groups of 3. No tiny leftover pair.
How to measure
- Count enrolled students, not seats — absent students shrink real group sizes on the day.
- Pick group size by task: 3–4 for discussion, 4–5 for projects, pairs for peer review.
- When the remainder is 1, never leave a solo group — the even split absorbs them automatically.
- Re-shuffle groups every few weeks so the same students do not always work together.
- For graded work, balance skill levels after randomizing rather than before, to keep it fair and random.
Assumptions & limitations
Planning estimate
- This tool plans group structure (counts and sizes), not membership — assign names by shuffling separately.
- "Even" means group sizes differ by at most one student, which is the fairest possible integer split.
- It assumes all students are present; absences on the day require re-running with the actual headcount.
- Results are a planning aid for classroom organization, not a statistical randomization service.
Frequently asked questions
Divide students by your target size and check the remainder. If it divides evenly, you are done. If not, use the even split: spread everyone across one more group so sizes differ by at most one. This calculator does that arithmetic and shows the exact group sizes.
Never leave a group of one or two while others have five — redistribute. The standard fix is the even split shown in the steps: e.g. 30 students into groups of 4 becomes six groups of 4 plus two groups of 3 instead of seven 4s plus a pair.
Plan the structure here, then shuffle the roster (a spreadsheet RAND column works) and deal students round-robin into the group slots. Dealing round-robin after a shuffle is equivalent to a random assignment.
Research and practice converge on 3–4 for discussion-heavy tasks (everyone talks) and 4–5 for projects (enough hands, manageable coordination). Pairs suit peer review. Larger groups invite free-riding.