Free tool
Bill split calculator
Add the items, tap who had what, and every person's total updates live — shared plates split among the people who shared them, tax and tip allocated in proportion to what each person ordered.
Tip is computed on the items subtotal (before tax), then split in proportion to what each person ordered.
All the math happens in your browser. Nothing you type leaves this page — no account, no sign-up, no server.
How the math works
Every amount is handled in whole cents, in three passes:
- Items: each item's price divides evenly among the people who shared it — and only them. Odd cents go to whoever's share was rounded down the most, so each item still sums to its exact price.
- Tax: the tax you enter is allocated in the same ratio as the item subtotals. Ordering 30% of the food means paying 30% of the tax.
- Tip: the tip percentage applies to the items subtotal (the customary pre-tax base), and the resulting tip dollars are allocated proportionally, just like the tax.
Because every pass uses largest-remainder rounding, the per-person totals always add up to the bill exactly — split $100.00 three ways and you get $33.34 + $33.33 + $33.33, not three $33.33s and a vanished penny.
A worked example
| Line | Alex | Blair |
|---|---|---|
| Steak $30.00 (Alex) | $30.00 | — |
| Salad $10.00 (Blair) | — | $10.00 |
| Fries $10.00 (shared) | $5.00 | $5.00 |
| Subtotal (70% / 30%) | $35.00 | $15.00 |
| Tax $5.00, split 70/30 | $3.50 | $1.50 |
| Tip $10.00, split 70/30 | $7.00 | $3.00 |
| Total — sums to $70.00 | $45.50 | $19.50 |
An even split of the same $70.00 bill would charge Blair $35.00 — a $15.50 overpayment for ordering a salad. That gap is why an even split works like a hidden tax on light orderers, and it's the entire reason this calculator splits proportionally. If you want the rule spelled out step by step, read how to split tax and tip proportionally.
FAQ
Bill Split Calculator questions
01 How does this calculator split tax and tip?
Proportionally to what each person ordered. First every item's price is divided among the people who shared it, which gives each person an item subtotal. Then tax and tip are allocated in the same ratio as those subtotals: if your items are 70% of the food, you pay 70% of the tax and 70% of the tip. It's the same rule the splitty app uses when it reads a receipt.
02 How are shared items handled?
A shared item splits evenly among the people who shared it — and only them. If three of you split $10.00 of fries, the calculator assigns $3.34 + $3.33 + $3.33, so the item still adds up to exactly $10.00. People who didn't touch the fries pay nothing toward them.
03 Why do the per-person totals always add up to the bill?
The calculator works in whole cents and uses largest-remainder rounding: it hands out the base amount to everyone, then distributes the few leftover cents one at a time to the shares that were rounded down the most. The result always sums to the exact bill — no missing penny, no invented penny.
04 Isn't multiplying everyone's items by 1.2-something the same thing?
Almost, and that's the problem. A flat multiplier (items × 1.23, say) approximates proportional allocation, but rounding each person independently means the shares rarely sum to the real total — someone silently eats the difference. It also breaks when tax is a fixed dollar amount rather than a clean percentage. This calculator allocates the actual tax and tip dollars instead, so the split is exact.
splitty does this from a photo of the receipt
Same math — shared items among sharers, tax and tip proportional — without typing a single line item. Point your phone at the check; 30 seconds, done.
