How expense splitting works: methods, math and calculators
Most splitting problems come down to choosing the right method and doing the math once. These guides explain each method with numbers, and the calculators do the arithmetic for you.
38 pages
Guides
- Guide How simplify debts works, with worked examples Simplify debts cuts the payments a group needs without changing anyone's total. Six IOUs worth $105 become 3 payments worth $50, with the arithmetic shown.
- Guide How to calculate shared expenses when not everyone is in on every bill Work out each person's share of every bill, subtract what they paid, and the nets add to zero. A worked example with three housemates and a $363 month.
- Guide How to figure out who owes who after shared expenses Add up what each person paid, divide by the people sharing, and subtract. Four friends and five expenses settle in 3 payments instead of 6 pairwise debts.
- Guide How to split $100 three ways (and the extra cent) $100 split three ways is $33.33, $33.33 and $33.34. How the extra cent works, the same method for $200, $50 and other totals, and a quick check.
- Guide How to split a bill by percentage, with examples The formula for splitting a bill by percentage, with three worked splits of $1,250 (60/40, 50/30/20 and 33/33/34) and what to do when percents miss 100.
- Guide How to split a bill unevenly when orders differ Split a $186 dinner when one person's cocktails cost $24: carve out her drinks, split the rest four ways. Plus the right method for four uneven situations.
- Guide How to split a bill with tax and tip, step by step Split a $120 bill with 8% tax and an 18% tip two ways: equal shares of $37.80, or by items at $88.20 and $63.00. Includes tip before or after tax.
- Guide How to split a receipt by item, with tax and tip A hand-worked $108.44 receipt: four diners, shared nachos, tax split in proportion and the one-cent fix. Then how to enter it in EvenOut's By item split.
- Guide How to split a taxi fare when drop-offs differ A $39 taxi fare for friends dropped at 3, 5 and 9 miles is $5, $9 and $25, not $13 each. See the segment method, the tip, and how to enter it in EvenOut.
- Guide How to split bills based on income, with the math Split a bill by income with one formula: bill times your income divided by everyone's income. Worked examples for $1,800 with two and three earners.
- Guide How to split bills with friends: take turns or keep a tab Taking turns to pay drifts. Six outings totaling $360 leave one friend $24 behind. See how a running tab fixes it, with the arithmetic for each friend.
- Guide How to split expenses: five methods, one worked example One $480 cabin bill for four people, split five ways: equally, by percent, by shares, by exact amounts and by item. See the sums and pick the method.
- Guide Minimum transactions to settle debts: the algorithm Settling N people takes at most N minus 1 payments, but not always the fewest. A five-person example needs 4 payments greedily and only 3 at best.
- Guide Scan a receipt to split a bill: how it works How EvenOut Pro splits a bill from a receipt photo: what it reads, how items, tax and tip are shared, what you cannot edit, and a 5-point check before saving.
- Guide Simplify debts: why you owe someone you never paid Simplify debts changes who you pay, never how much. A $36 chain from Zoe to Mo to Lee becomes one payment, plus a 5-step audit for your group.
- Guide Split expenses in two currencies without converting Track a €300 hotel and a £120 dinner as two balances, then settle each one or agree a rate once. Also what Splitwise and EvenOut do with currencies.
- Guide Split expenses in WhatsApp: a tally format and where it stops working Keep a running tally in a WhatsApp group chat: one post format, a four-person weekend settled in 3 payments, and the point where a ledger works better.
- Guide Split the bill evenly or pay for what you ordered? On a $160 dinner for four, an even split makes the $22 diner pay $18 too much. When evenly is fine, when to carve out one order, and when to go by item.
- Guide Splitwise low-level design: classes, splits and balances Design a Splitwise-style expense splitter: money in cents, one strategy per split method, net balances, simplify debts and a Java sketch that compiles and runs.
- Guide The formulas for splitting bills, method by method Eight bill splitting formulas with variables, a worked example and a check for each: equal, percent, shares, exact, by item, income, balances and payments.
- Guide Who owes whom: what it means and how to read it 'Who owes whom' asks who has the debt and who is owed. See the who versus whom rule, then read it on a three-person example where one $45 payment settles all.
Calculators
- Calculator Bill split ratio calculator: split by shares or ratio Enter a total and each person's shares, such as 7, 5 and 3, or a ratio like 3:2:1. See the price of one share and every amount to the cent.
- Calculator Debt simplification calculator: the fewest payments for four people Enter up to six IOUs among four people and see the fewest payments that settle them. The example turns six IOUs worth $175 into 2 payments worth $95.
- Calculator Income-based split calculator Enter a bill and each person's income to see each share in dollars and percent, and how far it sits from an equal split. Shares add up to the cent.
- Calculator Percentage split calculator Enter a total and each person's percent to see every share in dollars and cents. $1,250 at 60 and 40 percent is $750 and $500. Percents off 100 are flagged.
- Calculator Split bill calculator with tax, tip and discount Enter the subtotal, discount, tax and tip to split one bill equally. See the tip on the pre-tax and post-tax amount side by side, to the cent.
- Calculator Split bills fairly calculator: equal, income and use side by side Enter one bill, each person's income and how much each used it. See the equal, income and use shares side by side, plus the average of the three.
- Calculator Unequal split calculator: split a bill by item or amount Enter what each person ordered, the shared dishes, tax and tip. Tax and tip follow each order, and the shares add up to the receipt to the cent.
- Calculator Who owes who calculator Enter what each person paid to see every balance and the short list of payments that settles the group. Odd cents are shared out so it adds up.
Templates
Alternatives
- Comparison Apps that simplify debts: who does it and can you turn it off Ten apps compared on fewest-payments settling: which simplify debts, which let you switch it off, and a worked example. Facts as of October 2026.
- Comparison Best IOU app: tracking what friends owe you What an IOU app should do (running balance, part repayments, reminders) and how EvenOut, Splitwise, Splitser, Splid and payment apps compare for money lent.
- Comparison Receipt splitter apps compared (2027) Seven receipt splitter apps compared on what a scan costs, how items get assigned and where the photo goes, with one 3-person bill worked out to the cent.
Glossary
- Glossary Go Dutch: meaning and origin To go Dutch is to pay your own share of a meal or outing. On a $90 check it can differ from an equal split. Dictionary origin and wording included.
- Glossary IOU: meaning and examples An IOU is a written note that says I owe you. See what dictionaries say, three examples from a napkin to an app balance, and how it differs from shared bills.
- Glossary Settle up: meaning and what it does in expense apps To settle up is to pay what you owe. In an expense app it records a payment: owe $64.00, record $25, and $39.00 is still owed. Here is how it works.
- Glossary Split the bill: meaning and other ways to say it To split the bill is to divide what a group owes. A $60 bill for 3 is $20 each, or $28, $17 and $15 if you split by what each person ate.
- Glossary Split the difference: meaning, with money examples To split the difference is to agree on the midpoint of two numbers. $1,200 against $1,000 lands on $1,100, and a $60 dinner can land on $25 and $35.