Fair-Share Bill Splitter
Split rent and bills equally, by income or by room size, and see who owes whom.
A monthly bill splitter for couples and roommates. Mix methods bill by bill (rent by income, internet equal), see each person's amount to the cent, record who actually paid, and get the fewest payments to settle up. Prints a statement per person. One file, works offline, no login.
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One-time purchase, no subscription. Download link by email. Refund within 14 days if it doesn't help.
A calculator for splitting your own bills. Not legal or tax advice about leases or shared finances.
Fair-Share Bill Splitter
Sample couple, November 2026
$1,805 and $1,245
Jess's and Kai's shares a month, each about 33 to 35% of take-home
Rent is split by income in this sample. Change it to equal and both amounts move.
Try it here
This is the demo build with sample numbers. Saving and export are switched off.
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What you get
- Split each bill your own way: equal, by income, by room size (with a common-area share), custom percentages or fixed amounts
- Every share is to the cent and always adds up to the bill, and the page shows who takes any leftover cent
- Part months handled: someone who moves in or out mid-month pays for the days they are there, and the rest is split among the others
- Monthly log records who paid each bill, finds the fewest payments to settle up, and carries any balance into next month
- Compare equal, by income and by room size side by side, then print or copy a statement for each person
Who it's for
Couples moving in together and roommates who share rent and bills, and want one clear monthly picture of what each person pays and who owes whom, without redoing a spreadsheet every month.
Questions
Can I use different methods for different bills?
Yes. Each bill has its own method, so rent can be split by income while internet is split equally. Compare shows one bill under equal, by income and by room size side by side before you decide.
How does it deal with cents that don't divide evenly?
Every share is rounded to the cent and the shares always add up to the bill exactly. Leftover cents go to the largest shares first, one cent each, and the Results tab names who took them.
What if someone moves in or out part-way through a month?
Enter their move-in or move-out date on People. For that month they pay their usual share for the days they are there, out of the days in the month, and the rest is split among the others by the same method.
How does 'who owes whom' work?
On Monthly log you pick who actually paid each bill and any one-off shared costs. The tool works out each person's balance and shows the fewest payments that settle everyone. Mark the month settled and it is saved as a record that later edits to your bills never change, or leave it open and the balance carries forward.
Is this legal or financial advice? Where is my data kept?
No. It is a calculator for splitting your own bills and is not legal or tax advice about leases or shared finances. Your data stays in your browser on your device. Use Export to back it up and Import to move it.
Does it work on my phone?
Yes. Each tool is a single file that opens in the browser on any iPhone, Android phone, tablet or computer. There's no app to install.
Where do my numbers go?
Nowhere. Everything you type stays on your own device. The tools work offline and never send your data anywhere.
Is there a subscription?
No. You pay once and keep the file. Fixes to the version you bought are free.
Pay once,
$9
You get the file, free fixes to version 1.0.0, and your money back within 14 days if it doesn't help.
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