BILL SPLIT CALCULATOR
Shared items are divided equally; personal orders stay personal. Tax and tip follow each person’s actual share of the food — someone who ordered 40% of the subtotal pays 40% of the tax and tip. When tip is entered as a percentage, it is calculated from the pre-tax subtotal. Use the tip field for either a tip you choose or a service charge shown on the bill. This tool only shows the math; it does not decide whether a charge is required.
Updated June 2026 · Built by Lukáš, an architect in Prague.
Formula, worked example, rounding & limitations
Formula
subtotal_i = personal_i + shared ÷ Nshare_i = subtotal_i ÷ sum of subtotalstax_i = tax × share_i·tip_i = tip × share_itotal_i = subtotal_i + tax_i + tip_i- When tip is entered as %,
tip = sum of subtotals × tip% ÷ 100(pre-tax).
Worked example
- 4 people · shared $24 · personal $32 / $18 / $22 / $0 · tax $8.05 · tip 18%.
- Subtotals: $38 / $24 / $28 / $6 (sum $96). Tip: 18% of $96 = $17.28.
- Totals: $48.03 / $30.33 / $35.39 / $7.58 — together exactly $121.33.
Rounding
- Each person’s total is rounded to cents. If rounding leaves a cent difference, the extra cent is assigned deterministically so the per-person totals add up exactly to the bill total.
- Detail: leftover cents go to the largest fractional remainders first; ties go to the lower person number.
Limitations
- Each person’s order is entered as one amount — item-by-item entry is not modelled.
- Shared items are split equally among all people at the table.
- Whether a service charge is mandatory is not evaluated — only the math is shown.
- Nothing is stored: no accounts, no history, no payments.
Why isn’t an equal split always fair?
Because people order differently. If your meal was $18 and someone else had a $40 steak and cocktails, splitting equally means you pay for their dinner. A fair split divides shared items equally but keeps personal orders personal — tax and tip then follow each person’s actual share.
How are tax and tip split fairly?
Proportionally to what each person consumed, not equally. Someone who ordered 40% of the food pays 40% of the tax and 40% of the tip. When tip is entered as a percentage, it is calculated from the pre-tax subtotal.
What about people who did not drink?
Put drinks into the personal amounts of the people who ordered them, and keep only genuinely shared food in the shared total. Non-drinkers then automatically pay nothing toward the alcohol — no separate toggle needed.
What is the difference between a tip and a service charge?
A tip is voluntary and you choose it; a service charge is printed on the bill by the restaurant. Use the tip field for either one. This tool only shows the math; it does not decide whether a charge is required.
Do you save the amounts?
No. The calculation runs in your browser and we do not save your inputs. The Copy link button stores the numbers only in the link itself (the part after #), which is never sent to our server.