Bill & rounding
Attendee groups
Multiplier (1.0 = base). Raise to pay more, lower to pay less.
Extra the organizer pre-pays. Negative = pays less.
Who pays what
Enter a total and at least one person to split the bill.
When you split a restaurant or party bill in Japan, dividing the total by the number of people leaves awkward fractions like ¥2,857 that are hard to hand over, and the organizer usually ends up covering the difference. This warikan (bill-splitting) calculator turns the total and the attendees into a split that is easy to pay, fair, and collects exactly, using three practical features. (1) Rounding: round each person's share to ¥1, ¥10, ¥50, ¥100, ¥500, or ¥1,000, rounding up, down, or to the nearest. (2) Tiered shares: give each group a multiplier (for example boss ×1.5, regular ×1.0, newcomer ×0.5) so people pay more or less according to their position. (3) Organizer: designate one organizer, and the attendees pay clean rounded amounts while the organizer absorbs the remainder, so the money collected matches the bill to the yen. You can also have the organizer pre-pay an extra amount (treat everyone), which lowers what the attendees pay. The result lists each group's per-person amount, head count and subtotal, the organizer's payment (with how much more or less it is than their fair share), and the collected total with any surplus or shortfall. Everything is computed only inside your browser; the amounts and counts you enter are never sent to any server.
How to use
- Enter the total, then pick the rounding unit (¥100, ¥500, …) and how to round (up / down / nearest). Use "Example" to fill a common scenario fast.
- Add attendee groups and set each group's head count and multiplier (one group is fine if everyone pays the same; raise or lower the multiplier to make seniors pay more or juniors less).
- Turn on "Set an organizer" so the organizer absorbs the remainder and the collection matches the bill exactly. You can also set how much extra the organizer pays. Per-person amounts and the collected total update instantly.
FAQ
Are the amounts and counts I enter sent to a server?
No. The whole split is computed inside your browser; the total, head counts, and multipliers are never uploaded, stored, or transmitted. It works fully locally.
What's the difference between rounding up and rounding down?
Rounding up raises each share to the unit, so the money collected exceeds the bill and leaves a surplus. Rounding down lowers it, so the collection falls short. If you set an organizer, that surplus or shortfall is absorbed by the organizer, making the collection match the bill exactly.
How do tiered shares (multipliers) work?
Use them when people should pay different amounts by position or how much they consumed. For example boss ×1.5, regular ×1.0, newcomer ×0.5 splits the total in that ratio before each per-person amount is rounded. Leave every multiplier at 1.0 (one group) for an even split.
How do I make the organizer pay more?
Set an organizer and choose round-down: the attendees pay less and the organizer covers the difference, which naturally makes the organizer pay more. You can also enter an "organizer extra" amount so the organizer pre-pays that much and the rest is split among the attendees, lowering their shares (a negative value makes the organizer pay less).
Can the collected total differ from the bill?
With an organizer set, the organizer absorbs the remainder, so the collected total always equals the bill. Without an organizer, everyone pays a rounded amount, so rounding up leaves a surplus and rounding down a shortfall; the result shows that difference so you can adjust on the day.