Split a Bill from Start to Finish

Step 1 — Start from the total, not the bill

Five people look at a $184.00 bill. The amount that actually leaves the table is $235.52: the subtotal, plus 8% tax at $14.72, plus a 20% tip of $36.80 worked out on the pre-tax amount. That total is the number a split divides — not the $184.00 printed under the food.

Order matters here. The tip is charged on the $184.00 before tax, so it is 20% of $184.00, not 20% of the after-tax figure. A tip charged after tax would come to $37.54 and lift the total to $236.26, and every share below would move with it.

If the five split the $184.00 subtotal instead, each pays $36.80 and the table is $51.52 short of what it owes. An even share of the real total is $47.104, so each person ends up $10.304 short of what they should have handed over.

This step is what the split bill calculator does first: enter the bill, set tax and tip, and read the total before anyone decides who owes what.

Step 2 — Pick the basis before anyone pays

The basis decides who carries which slice of the same total. The total does not move: $235.52 sits under every basis. What moves is the spread — the distance between the largest share and the smallest.

Under an even split the widest gap between two people is one cent. Under the 30/25/20/15/10 basis it is $47.11 — the same money, distributed on a different rule. Neither result is automatically the right one; the point is that the basis is a decision the group makes before the money moves, and it can be made on the screen instead of argued about at the table.

Weights that do not add up to 100 are handled too: the split by percentage page scales them and says so, so a set of weights like 40/30 still produces shares that sum to the total.

Step 3 — Allocate the whole total once

Each person's exact share is their weight times the total. Thirty percent of $235.52 is $70.656, and that is the number the arithmetic uses. Money only moves in whole cents, so each exact share is rounded down to the cent first: 70.65, 58.88, 47.10, 35.32, 23.55. Those floors add up to $235.50, two cents short of the total.

Theo's share lands on a whole cent exactly, so nothing is rounded for him. The other four each carry a fraction of a cent. The calculator allocates the full $235.52 once, at the end, from these exact values — it does not round each amount on its own and add them up afterwards, because a column of independently rounded cells can drift a cent away from the total it came from.

Step 4 — Place the leftover cents

Two cents are left after the floors. They go to the two largest fractional parts, in order: Ronan's .8 and Mara's .6. Mara's $70.65 becomes $70.66, Ronan's $35.32 becomes $35.33, and Theo's share stays at $58.88 because it never had a fraction to round.

When two fractions tie, the first person in the list takes the cent. That is why the even-split column in Step 2 reads 47.11, 47.11, 47.10, 47.10, 47.10: all five fractions are identical, so the first two names take the two leftover cents and the order is fixed before the total is touched.

The rule works the same way on any bill between any number of people, and the leftover cent page runs it on its own cases — $10.00 across three people, $100.00 across three, $0.05 across two — with the exact share kept at full precision.

The chain as one pass

Four steps, one answer. Each step below is a page on this site that runs that part of the chain in the browser, with nothing to sign up for and nothing uploaded.

1. Enter the bill and the adjustments. Open the split bill calculator, type $184.00, set tax to 8% and tip to 20%, and read the $235.52 total off the same screen this page shows.
2. Choose the basis. Leave it even for an equal split, or switch to split by percentage for weights like 30/25/20/15/10 — including weights that do not total 100.
3. Read each person's amount. The calculator lists the five shares, allocated once from the total in whole cents.
4. Check the leftover. The leftover cent page shows the same largest-remainder placement this page used for the last two cents.

Where this fits with the rest of the site

This page is the chain end to end. The other pages open up one link of it: split bill line by line shows the arithmetic inside a single itemised receipt; split bills by income runs one bill under three bases at once; monthly household bill runs the same chain for rent and utilities every month; split by income weights shares by what each person earns instead of by percentages.

Every calculator here runs the same integer-cent arithmetic, so a figure on this page can be checked against the same figure on another. Nothing is uploaded — the privacy page says what that means, and the about page says who builds these pages.