How it works
Billsplitly does all the math in your browser. Here's what each option does.
Split methods
- Equally: everyone ticked under "Split between" pays the same.
- By income: each person pays income ÷ total income. Enter monthly incomes in the People section. Any period works as long as it's the same for everyone.
- By room size: each person pays their room's square footage ÷ the total. Square meters work too.
- By percentage: type each person's percent. It should add up to 100.
- By custom shares: give people "parts". With 2, 1 and 1, the first person pays half.
Settling up
For each person, Billsplitly takes what they paid and subtracts their share. A positive balance means they're owed money, and a negative balance means they owe. It then matches the biggest debts with the biggest credits. A household of N people needs at most N−1 payments, so you don't end up sending money around in circles.
Privacy
Nothing leaves your device unless you share a link. The link stores the split in the part after "#", which browsers don't send to servers.
FAQ
What is the fairest way to split rent with roommates?
There's no single fair way. Equal splits work when rooms are similar. If one room is bigger or has a private bathroom, split by room size. If incomes are very different, splitting by income keeps rent at the same share of everyone's pay. Billsplitly lets you use a different method for each bill.
How do I split rent by income?
Add each person's monthly income, then set the rent bill to "By income". Each person pays their income divided by the household's total income. For example, $6,000 and $4,000 incomes split $2,000 rent as $1,200 and $800.
How do I split rent by room size?
Enter each bedroom's square footage and choose "By room size". Many households split shared space equally and only weight the bedrooms. To do that, add rent as two bills: one shared part split equally and one bedroom part split by room size.
How should roommates split utilities?
Most roommates split electricity, gas, water and internet equally, because usage is hard to track per person. If someone works from home or runs a space heater, a custom split like 60/40 is common. Use "By percentage" or "By custom shares" for those bills.
What does "who owes whom" mean in the results?
Billsplitly adds up what each person paid and what each person owes, then works out the smallest set of payments that settles everyone. With N people you never need more than N−1 transfers.
Can one person be left out of a bill?
Yes. Untick a person under "Split between" on that bill. For example, leave out the roommate who doesn't use the streaming service.
Is my data saved or sent anywhere?
Your numbers stay in your browser's local storage on your device. Nothing is sent to a server. A share link puts the split inside the link itself, so only people you send it to can see it.
How do I share the split with my roommates?
Tap "Copy share link" and paste it into your group chat. When roommates open the link, they see the same people, bills and results. You can also copy a plain-text summary or print the page.
What if the percentages don't add up to 100%?
Billsplitly shows a warning and splits the bill in proportion to the numbers you entered, so 50 and 30 becomes 62.5% and 37.5%. Fix the numbers if that isn't what you meant.
How are cents rounded?
Every split adds up exactly to the bill. Any leftover cents go to the people whose shares were closest to rounding up, so no one is ever more than one cent off.