Split Bill Calculator
Split a total bill among a group and see exactly how much each person pays. Supports plain even splits as well as weighted splits (e.g. the organizer pays less). Rounds to the nearest 1, 10, or 100, and spreads any leftover fairly instead of dumping it on one person. Everything runs in your browser — the amounts you enter are never sent anywhere.
The amounts you enter are processed entirely in your browser and are never sent anywhere.
Enter the total and number of people, then select Calculate.
Amount per person
| Person | Amount | Rounding adjustment |
|---|
This matches the total amount you entered.
How to use
- Enter the total amount and the number of people. Names are optional — anyone left blank shows as "Person 1", and so on.
- Leave it as an even split, or turn on "Use weighted split" and set a ratio per person to make some people pay more or less.
- Pick a rounding unit (1, 10, or 100) and direction, then select Calculate. The result table shows exactly whose payment got a rounding adjustment.
How it works
How the amount is calculated
Each person's share starts as a "raw" amount based on their weight (or an equal weight for everyone, if you're not using a weighted split), then gets rounded to the unit you chose (1, 10, or 100).
person's raw share = total amount × that person's weight ÷ sum of everyone's weight
Without a weighted split, every weight is 1, so this reduces to a plain total ÷ number of people.
How the leftover is handled
If everyone's share is simply rounded up (or down) independently, the sum stops matching the total you entered. For example, rounding ¥1,000 split three ways up to the nearest ¥10 gives ¥340 each — a total of ¥1,020, ¥20 too much.
This tool doesn't dump that ¥20 on one person. Instead it spreads the adjustment across whoever benefited most from the rounding, ¥10 at a time, until the sum matches again — in this example, ¥330 / ¥330 / ¥340 (which adds up to exactly ¥1,000).
When the total isn't a multiple of the rounding unit
If the total itself isn't a multiple of your rounding unit (say, ¥1,005 rounded to the nearest ¥10), it's mathematically impossible for every person's share to stay a multiple of ¥10 while still summing to ¥1,005. In that case the tool distributes as much as it can in rounding-unit-sized steps, then adds whatever remains (less than one unit) directly onto whichever person is next in line. That one person's amount won't be a clean multiple of the rounding unit — this is shown as an adjustment in the results.
How ties are broken
When two people are equally due for a rounding adjustment, the one entered earlier in the list goes first. That makes the result deterministic: the same inputs always produce the same output.
FAQ
Are the amounts I enter sent anywhere?
No. The calculation happens entirely in your browser, with no connection to any server. Once the page has loaded, it works offline too.
Who ends up paying the rounding leftover?
It isn't dumped on one person (like the organizer). The adjustment is spread across whoever benefited most from the initial rounding, one unit at a time. The results table marks exactly whose payment was adjusted.
Can I make one person pay less, like the organizer?
Yes. Turn on "Use weighted split" and set a lower weight for that person; everyone else keeps the default weight of 1 unless you change it.
What happens if the total isn't a multiple of the rounding unit?
For example, splitting ¥1,005 to the nearest ¥10 can't keep every share a clean multiple of ¥10 while still summing to ¥1,005. The tool rounds as much as it can, then adds the remaining ¥5 straight onto whoever is next in the adjustment order — only that one person's amount ends up not being a round number.
How many people can I split a bill among?
Between 2 and 50 — enough for typical group dinners and trips.
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