Bill Split Calculator
Split one bill evenly, or settle a whole trip of bills with different people paying.
How it works
This page does two jobs. The “One bill” tab splits a single bill evenly: add the service charge, divide by the number of people, round to something payable. The “Whole group” tab does the harder one — a whole trip of bills, a different person fronting each of them, and not everybody present at every meal.
Halving a bill is mental arithmetic. Splitting it seven ways with a 5% service charge, and landing on something payable in cash, is where a calculator earns its place.
The service charge is added before the division rather than after. That is the correct order, because the charge applies to the whole bill rather than to each share — the two orders agree for an even split, but being explicit costs nothing.
The rounding solves a very local problem: the smallest note in circulation in Vietnam is 1,000 đồng. A bill of 415,000 split three ways is 138,333 each, which nobody can hand over in cash. Rounding up to 139,000 makes it payable, and the 2,000 surplus is shown rather than quietly disappearing.
If everyone is transferring rather than paying cash, turn rounding off: a transfer settles to the đồng, and there is no reason to over-collect.
In group mode each bill is divided by the shares of the people who were on it: one share each by default, two for somebody eating for two. The shares are always whole đồng and always add back up to the bill exactly — nothing is lost or invented, not even when 400,000 goes three ways.
A trip is not settled in one sitting, so events can be saved: name one, press save, and its participants and bills stay in your browser for next time. Archive it once everyone has paid. Nothing is written unless you press save — it is a choice you make, not a default.
The answer at the end is not a tangle of who-owes-who but the shortest list of transfers that clears it. Five people over four meals can generate dozens of crossing debts; the tool nets them into one balance per person, then matches the largest debt against the largest credit, so a group of n never needs more than n − 1 payments.
Formula
total = bill × (1 + tip) • each = round up(total ÷ people) • surplus = each × people − total
Rounding is always up, never to nearest. Rounding down collects less than the bill, and whoever settles it makes up the difference out of their own pocket.
Worked example
A bill of 415,000 split three ways, rounded up to 1,000:
- Exact share
- 415,000 ÷ 3 = 138,333.33
- Rounded up
- 139,000 each
- Collected
- 139,000 × 3 = 417,000
- Surplus
- 417,000 − 415,000 = 2,000
The 2,000 does not vanish — it ends up with whoever settles the bill. Showing it keeps the table honest about what just happened.
Frequently asked questions
Why round up rather than to the nearest?
Rounding down collects less than the bill, leaving whoever pays to cover the gap. Rounding up always covers it, and the surplus is shown.
What should I round to?
To 1,000 for cash, since that is the smallest note in circulation. To 5,000 or 10,000 to keep it simple. Off entirely if everyone is transferring.
What happens to the surplus?
Usually the person who settled the bill keeps it, as a rough compensation for fronting the money. Leaving it as a tip is the other common answer.
Is the tip added before or after the split?
Before. The charge applies to the whole bill, so it goes into the total and the total is divided. For an even split both orders agree, but this is the right one in principle.
Can I split it unevenly?
Use the “Whole group” tab. Every participant has a share box: 1 for a normal appetite, 2 for someone eating for two, 0 for someone who only came along. The percentage beside it says what that works out to as a fraction of the bill.
What if several people paid for different bills?
That is exactly what the “Whole group” tab is for. Add each bill with who paid it and who was there; the tool nets everything into one balance per person and hands back the shortest list of transfers that squares the group up.
Why so few transfers instead of settling each bill?
Because only the final balances matter. If An owes Bình 100,000 and Bình owes Chi 100,000, An can pay Chi directly and both debts are gone. That is why a group of n people never needs more than n − 1 payments.
Can I save an event and come back to it later?
Yes. On the “Whole group” tab, name it and press “Save event”; from then on every change is saved automatically. Saved events appear as a list with their total and how many transfers are still outstanding, and each one can be reopened, archived once it is settled, or deleted.
Where are saved events kept, and are they sent anywhere?
They live in the localStorage of the browser you are using, and are sent nowhere — this site is static HTML with no server to receive them. So they do not sync to your other devices, and clearing site data in your browser removes them. Nothing is written until you press save.
Can I leave someone off a bill they were not there for?
Yes. Each bill has a “Split between” list — tick only the people who were actually there. Anyone unticked pays nothing towards that bill while still counting on every other one.
What if the service charge is already on the bill?
Leave the tip at 0 and enter the final total as the bill amount. If you want to add something on top of a charge that is already there, put that in the tip field.