How to split bills based on income, not headcount.
An equal split charges the same rupee amount to every income. A split by income charges a similar share of each person's pay instead, so the bill costs everyone roughly the same amount of effort, not the same number of rupees.
The arithmetic, in words.
Add up everyone's income to get a total. Each person's share of the bill is their own income divided by that total, multiplied by the bill. A person earning twice as much as another pays twice their share, in proportion, not in a fixed extra amount. The calculator uses the same largest-remainder method as the split calculator, so the shares always add up to the bill exactly, to the cent, with any leftover rupee going to whoever is already paying the largest share.
Nothing typed here is sent anywhere. It runs in the browser, and the shareable link carries only the amount, the names and the incomes you chose to put in it.
How to use it.
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Enter the total bill
Type the full amount due, and pick the currency.
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Add each person
Add a row for everyone sharing the bill, named however you like.
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Enter each person's income
A monthly take-home figure works well. Equal incomes give an equal split.
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Share the result
Copy the link and send it to the group. It carries the bill, the names and the incomes, nothing else.
Equally is not always fairly.
Splitting by agreed proportion
The group agrees the proportions and enters them. There is no salary field and no bank connection, so there is nothing here to leak.
Equally is not always fairly.
The group agrees the proportions and enters them. There is no salary field and no bank connection, so there is nothing here to leak.
One bill, three incomes, one agreed proportion.
A household bill against three different incomes. The three shares add back to the bill exactly.
How a proportion is agreed, and how it changes.
Set once at the household, applied to everything after it, visible to everyone, and changed only by agreement. A change applies from the day it is agreed.
Where this meets the rest of the ledger.
A fair split answers who owes what. It does not, on its own, show what a shared bill did to your own budget. In Spendthrift, the payer's own share lands as real spending in their envelope, and the rest is recorded as owed back, automatically. See the bridge, on the home page.
Questions.
Why split by income instead of equally
An equal split treats a rupee the same for everyone, but a rupee costs a higher earner less of their month. Splitting by income keeps the burden proportionate, so the same bill takes a similar bite out of everyone's pay, not the same rupee amount.
What income figure should we use
Whatever the household agrees is fair and is willing to state, most often monthly take-home pay. The calculator only needs the proportion between people, not the exact rupee figure, so a rounded number works.
Does this work for rent as well as bills
Yes, the arithmetic is identical. For rent specifically, see the split rent app, which can weight by room as well as by income.
Is an equal split ever the fairer choice
Often, yes, especially for a shared grocery run or a group dinner where the point is convenience, not proportionality. Set every income to the same number and this calculator gives the plain equal split.