Free tool
Split an expense by percentage
Enter the amount, then each person's percentage: the tool checks that the percentages add up to 100% and works out every share to the cent.
The expense to split
Percentage per person
Percentage with up to two decimals, for example 33.33. The percentages must add up to 100%.
Total
€0
What everyone owes
Enter the amounts to see the split.
Leftover cents go to the shares hit hardest by rounding, so the amounts split add up exactly to the total entered.
Everything is computed in your browser: nothing is stored or sent.
Whole-cent arithmetic with a largest-remainder distribution of the leftovers: the shares are checked against the total by automated tests.
For tracking several expenses over time, with your friends.
When a percentage key makes sense
Percentages are the clearest key whenever the rule is a decision rather than a formula: 60/40 between two business partners, 50/30/20 in a shared let, 70/30 between two households on a joint gift. Everyone sees at a glance what they owe and why.
It is also a key that is simple to reuse: once agreed, it applies to every expense of the same kind without reopening the discussion.
Why the total must be exactly 100%
If the percentages add up to less than 100%, part of the expense is assigned to nobody; if they exceed it, you are splitting more than was actually spent. The tool therefore warns you until the total is exactly 100%.
For three people sharing equally, 33.33 / 33.33 / 33.34 works perfectly: the last decimal absorbs the remainder. Two decimals are enough for any everyday split.
Percentages or shares?
Percentages are ideal when the key is already expressed that way. If you think in terms of "one share per adult, half a share per child", shares are more natural: they avoid recalculating percentages every time the group changes.
Frequently asked questions
Can I use decimals?
Yes, up to two decimals, which allows fine splits such as 16.67%. Beyond that the difference falls below one cent on most expenses.
What happens if the total is not 100%?
The tool flags it and still distributes the whole amount in proportion to the percentages entered, so no cent disappears. Adjust the key to get the result you expect.
How do I reuse this key later?
This tool stores nothing. To apply the same key to a series of expenses, create a Pivunio group: the custom split is saved with each expense.
Editorial review — Written and reviewed by the Pivunio team. The methods described here are the ones the app itself uses, and they are covered by automated tests.