Rent Split Calculator

Splits the rent between housemates by room size and extras, divides utility bills, and works out who should send how much to whom. Use it when rooms differ in size or someone moved in mid-month.

How to use

1. On the "Rent" tab, enter the "Total rent" and choose "How to split". With "Mixed", set the "Shared space part".
2. For each room, enter the "Room size" and "Extras" and the names of the people living there. Press "Add someone to this room" for a shared room.
3. On the "Bills" tab, enter each bill and choose equal, by days stayed or by usage share.
4. On the "Settle up" tab, choose who paid the rent and the bills to see the "Transfers". Press "Copy summary" to paste it into a group chat.

How it works

• Mixed method: share = rent × shared part ÷ number of people + rent × (1 − shared part) × room weight ÷ total weight ÷ people in the room, where room weight = size × (1 + extras).
• Shares are rounded to the step under "Round to"; any odd remainder goes to one person, so the shares always add up to the total.
• Transfers are worked out with the fewest payments possible.
• Names, amounts and incomes are saved only in this browser; "Clear saved data" removes them.

Questions and answers

How do you split rent fairly when rooms are different sizes?

A common way is to split the shared space equally and the rest by room size. With 3,000 rent, a 30% shared part and rooms of 130, 100 and 100 sq ft, the shares come to about 1,127, 936 and 936.

How does a shared bedroom work?

The two people split that room's part in half, and each pays one person's portion of the shared space.

How do you split bills when someone moved in mid-month?

Choose "By days stayed" and enter the days each person lived there. Someone who stayed 15 of 30 days pays half as much as the others.

Can rent be split by income?

Yes. Choose "By income" and enter each person's income; the rent follows the income ratio. Incomes stay on this device.