Spendwise
How this split works
The tip is calculated on the pre-tax bill, added to the total, and the total is divided by the headcount. That order matters: tipping on the post-tax amount inflates the tip by whatever the local tax rate is, and on a 187.40 bill with 15% it is 4.20 that nobody intended to leave.
The division is in whole cents, never in floating point. A bill of 215.51 across four people does not divide evenly, so the shares are 53.87 each and one person pays 53.88. The alternative — rounding every share up — is how a collector ends up with a quiet profit, and how a group chat argument starts.
Tip, service charge, and what the bill already includes
Tip norms travel badly, and a calculator cannot fix that; it can at least not make it worse. Three rules that keep the arithmetic honest:
- Check for a service charge first. A line saying "12.5% service" means the tip is already on the bill. Set the tip to zero and split the total, or you are tipping twice.
- Tip on the subtotal, not the tax. Enter the pre-tax figure. Where the bill shows only a grand total, divide by one plus the tax rate to recover it.
- Agree before the card lands. Deciding the tip while the terminal asks for a percentage is how a table of five ends up paying 25%.
When an even split is the wrong answer
An even split is fast and usually fair enough. It stops being fair when the spend is lopsided — one bottle of wine, one steak, one person who ordered a starter and left early.
- By item. Assign each line to whoever ordered it, split shared plates and the tip evenly, then add. More precise, slightly awkward, and the right call when the gap is large.
- By course. A middle path: separate drinks and dessert, split food evenly. Handles most of the awkwardness without itemising.
- Not by income. Proportional-to-salary splits make sense for rent and bills, not for dinner. Someone who earns more does not owe more for your pasta.
For recurring shared costs — rent, utilities, a flat's groceries — the even split is usually the wrong default too, because consumption is not even. A per-person weighted split (two people in the big room, one in the small) is more durable than an equal one that someone quietly resents.
Splitting once, tracking all month
A calculator answers one dinner. The harder version is a shared flat or a trip where twenty small payments happen over two weeks and nobody remembers who covered what. That is a ledger problem, and a chat thread is a poor ledger.
In Spendwise a group is its own ledger — its own budget, its own categories — so a trip does not contaminate the personal month. Expenses added to the group sit alongside people balances for money lent and borrowed, and the group screen shows who is up and who is down. The trade is explicit: one person keeps the ledger. There is no shared real-time editing, so the group needs one keeper who logs, and everyone else sees the total.
When the trip ends, the numbers are already there: no reconstruction from screenshots, and the monthly report carries the group spend separately from the household budget.
Frequently asked questions
Should the tip be calculated before or after tax?
On the pre-tax subtotal, which is the custom in the United States and the simpler of the two reads. Enter the pre-tax bill in this calculator and it is correct on the first pass. Where a service charge is already on the bill, set the tip to zero rather than adding a second one.
How do I split a bill unevenly?
Settle the items first and split the remainder. Assign each dish to whoever ate it, divide shared plates and the tip evenly, and add the two parts. Income-proportional splits are defensible for rent, not for a restaurant bill.
What is the fairest way to handle the leftover cent?
Give the extra cent to one person, or to whoever is collecting. Never round every share up: four people rounding a 53.87 share to 54 pays 216.00 against a 215.51 bill, and the collector pockets the difference without deciding to.
Does this calculator store the bill?
No. Everything is computed in the page, nothing is uploaded, and there are no cookies or third-party scripts. Closing the tab discards it.
How does Spendwise handle shared expenses?
A group is its own ledger with its own budget and categories, so a trip or a shared flat does not mix with personal spending. One person keeps the ledger, and the app tracks who owes whom through people balances. It does not offer shared real-time editing, so a group needs one keeper rather than two editors — see the longer version.