How this calculator works
Pick one of three rules and the shares follow. Evenly divides the total by the head count. By item assigns each line to whoever ordered it and divides anything shared between the people who shared it. By income divides in proportion to a weight you supply. A fourth control decides where the tip and the tax go — with the bill, or equally per head — and since that changes the answer on two of the three rules, both are shown rather than one being picked for you. Every share is worked out in whole cents, so the parts always add back up to the total. For one bill and one tip with no splitting, the tip calculator is the simpler tool, and the rest of the tip calculators share the same arithmetic.
The formula
Their share = Amount × (Their weight ÷ Everyone's weights)
Weight, evenly = 1, for everybody
Weight, by item = What they ordered + their part of anything shared
Weight, by income = Their income, or their income above a floor you set
Rounded up = Their share raised to the next $1 or $5
Substituted: Cara’s $22.00 of a $92.00 bill is 23.9% of it, so she carries 23.9% of the $18.40 tip — $4.40. The spare cents from any division are handed out one each rather than rounded away, which is why the shares reconcile exactly.
Worked examples
Example 1 — a $92.00 table where everyone ordered differently
- Ann:
- Steak $32.00
- Ben:
- Pasta $18.00
- Cara:
- Salad $12.00
- Shared:
- Wine $30.00, three ways
- Tip:
- 20% (top of the published range)
- Each person's items: $42.00 · $28.00 · $22.00
- Tip on the whole bill: $92.00 × 20% = $18.40
- Tip allocated by item share: $8.40 · $5.60 · $4.40
They pay: $50.40 · $33.60 · $26.40
Sharing the tip per head instead makes it $48.14, $34.13 and $28.13 — Cara pays $1.73 more for having ordered the cheapest thing. The table hands over $110.40 either way.
Example 2 — $1,800.00 of rent between two different incomes
- Higher earner:
- $4,000.00 a month
- Lower earner:
- $2,500.00 a month
- To split:
- $1,800.00
- Evenly: $900.00 and $900.00
- By gross income: $1,107.69 and $692.31
- By income above a $1,200.00 floor: $1,229.27 and $570.73
The lower earner pays: $900.00, $692.31 or $570.73
Three defensible answers to the same question, and the spread between them is real money. None of them is more correct than the others — the calculator computes the one you have agreed on.
Why the tip and the tax are allocated proportionally
Once a table has agreed to pay for what each person ordered, a second question is left unasked: who pays the tip and the tax on top. The default here is that they follow the bill. Both are a flat percentage of what was bought, so if Cara’s food is 23.9% of the bill then 23.9% of the tax was charged on her food — arithmetic, not a rule anyone published. Sharing them per head instead charges the person who had a salad the same tax as the person who had the steak. That convention is common, so it is offered, but it is a transfer from the lighter eater to the heavier one and worth sizing before you agree to it.
| Person | Their items | Tip follows the bill | Tip shared per head | Difference |
|---|---|---|---|---|
| Ann | $42.00 | $50.40 | $48.14 | −$2.26 |
| Ben | $28.00 | $33.60 | $34.13 | +$0.53 |
| Cara | $22.00 | $26.40 | $28.13 | +$1.73 |
Splitting by income is a convention, not a calculation
“Proportional to income” sounds like one thing and is at least three, and they do not agree. Strict proportionality to gross income is the simplest and has a sharp edge: somebody with no income pays nothing, which is the rule working as defined rather than a fault, but it is not always what a household meant. Counting only income above a floor widens or narrows the gap depending on where the floor sits, and the floor is always yours to choose — this site does not publish a cost-of-living figure and will not supply one, because a number that decides who pays the rent should not arrive from a calculator by default. Agreed shares are the third option, for a household that settled on 60/40 long ago. There is no authority to appeal to here and none is cited: the calculator computes the convention you have agreed on, it does not arbitrate what is fair.
| Method | Weight used | Higher earner | Lower earner |
|---|---|---|---|
| Evenly | 1 each | $900.00 | $900.00 |
| Gross income | Their income | $1,107.69 | $692.31 |
| Income above a floor | Their income − $1,200.00 | $1,229.27 | $570.73 |
| Agreed shares | Whatever you both settled on | Your figures | Your figures |
Key facts
- Dividing $100.00 between three people in whole cents gives $33.34, $33.33 and $33.33 — the spare cent has to go to somebody, and a splitter that rounds each share on its own loses it.
- New York Tax Bulletin TB-ST-320 states that voluntary gratuities a customer leaves are not taxable, which is why sales tax on a restaurant bill is worked out before the tip rather than after it. Sales tax rules are set state by state.
- Under 29 CFR § 531.52, whether a tip is given and how much it is are determined solely by the customer — so where a split puts the tip is an agreement between the people at the table, not a rule.
- On a $92.00 bill split by what each person ordered, sharing a 20% tip equally per head instead of in proportion to the items costs the lightest eater $1.73 more.
Rent, groceries and other shared household costs
Nothing above is specific to a restaurant. A rent split, a utility bill or a grocery run is the same arithmetic with the tip set to none: an amount, some people, a rule for dividing it. Rent between partners on different salaries is the income split; a house share where one room is bigger is the agreed-shares split; a supermarket trip where two of four people are buying for the household is the itemised split with the shared lines claimed by everyone. For a recurring cost, agree the rule once rather than re-negotiating it monthly — and write down which definition of income you used, because “we split it by what we earn” is not a specification. For rounding a figure up or down generally, use the rounding calculator.
Who should use this and when
Reach for it at the end of a meal where the card machine is waiting and somebody has already said “let’s just split it” — the itemised mode exists to make the alternative take fifteen seconds rather than five minutes. It also suits the quieter version of the same problem: two people setting a standing arrangement for rent, where the question is not the arithmetic but which rule to adopt, and three answers side by side beat being handed one. For a salon visit where one tip is divided between the people who served you, the haircut and salon tip calculator is built for that shape instead.
Tips and common pitfalls
- Check the shares still add up to the bill. Rounding each person’s share on its own is how a split quietly loses or invents money. Here the spare cents are handed out and any rounding-up is shown as its own line.
- Rounding up per person is not a rounding error. Four shares each rounded to the next dollar can add several dollars. That usually becomes extra tip, which is fine — as long as everyone knows it happened.
- Agree the income definition before the number. Gross, after-tax and above-a-floor give materially different splits. Discovering that after the money has moved is worse than a minute spent first.
- Watch for a service charge already on the bill. If a gratuity has been added for you, adding a tip on top tips twice — and in some states a mandatory charge is taxed where a voluntary tip is not.
Frequently asked questions
How do you split a bill between friends?+
Divide the total by the number of people and hand out the spare cents rather than dropping them: $100.00 between three is $33.34, $33.33 and $33.33. An even split is the right default when everybody ordered roughly the same.
How do you split a bill when everyone ordered different things?+
Assign each item to whoever ordered it, divide anything shared between the people who shared it, then allocate the tip and the tax in proportion to those subtotals. On the $92.00 table below that gives $50.40, $33.60 and $26.40.
Should the tip and tax be split evenly or by what each person ordered?+
Both are used and they give different answers. Sharing them per head is simpler but costs the lightest eater more — on the example bill it moves Cara from $26.40 to $28.13. The calculator shows both at once.
How do you split bills based on income?+
Give each person a weight and divide the bill in proportion to it. Strictly by gross income, $1,800.00 between someone on $4,000.00 and someone on $2,500.00 a month is $1,107.69 and $692.31. Which weight to use is an agreement, not a calculation.
How do you split rent when one person earns more?+
The same conventions apply to rent as to a restaurant bill. On the figures above, an even split is $900.00 each; by gross income the lower earner pays $692.31; counting only income above a $1,200.00 floor they pay $570.73. Pick the one you both agree with.
Who owes who when one person pays the whole bill?+
Enter what each person actually handed over and the calculator works out the fewest payments that square everybody up — never more than one fewer than the number of people. If the bill is only part-paid, the shortfall is shown separately, because that is owed to the venue rather than to anyone at the table.
Is a tip included in sales tax?+
In New York, no: Tax Bulletin TB-ST-320 states that voluntary gratuities a customer leaves are not taxable. That is why the tax on this page is worked out on the bill before the tip. Sales tax rules are set state by state, so check your own state's guidance.
Related Tip Tools
Work out the tip on any bill, add sales tax, round the total up, or work backwards from a total you already paid.
Tip and Sales Tax CalculatorCompare tipping on the pre-tax subtotal against tipping on the tax-inclusive total, see the difference in dollars, and check how an automatic gratuity interacts with sales tax.
Haircut & Salon Tip CalculatorWork out the tip for a haircut, colour, barber visit, manicure or pedicure, and split one tip between a stylist and an assistant.
Tip Percentage CalculatorPick a tip percentage and see what it means in dollars, check it against the published US tipping range, and scan a $5–$200 tip chart at 10%, 15%, 18%, 20% and 25%.
Food Delivery Tip CalculatorWork out the tip for a food, pizza or grocery delivery — kept separate from the delivery fee — with the published per-order minimum, plus takeout and pickup guidance.
Estimates & assumptions
- Every share is computed in whole cents and reconciles to the total exactly. Where rounding each share up creates a surplus, that surplus is shown as its own line and never folded silently into the tip.
- There is no authority on how to split a bill by income. The three weightings offered here are conventions, named as such, and the floor for the income-above-a-floor method is always a figure you supply — this site does not publish one.
- Tipping is customary, not a legal requirement. The 15%–20% range shown for table service is quoted from a published etiquette source and varies by region and establishment. These are US conventions.
- The sales tax treatment quoted is New York's and is cited as such. Sales tax rules, and whether a service charge is taxed, are set state by state; this site holds rates for no state.
- This tool does not model who is legally liable for a bill, split-payment card processing, or currency conversion.
Figures are for everyday planning only and are not financial, tax, or legal advice. Where a range or a rule is quoted, follow the source link and read it in full.