What share of the rent should count as common space?

There is no rule; 25–35% is typical for a flat where the living room and kitchen are generous. A shared room with a small kitchen might use less. Agree on the number once and keep it each month.

Should rent be reduced when someone is away?

Usually not — their room is still theirs. That is why only the bills follow days at home, while rent follows room size. If your flat does reduce rent for absence, use the group expense splitter with shares instead.

Can I use this for a flat with a couple sharing a room?

Yes. Add the couple as one entry for the room-size split, or as two people with half the room each — the result is the same for rent. For bills, two entries counts both of them.

Rent Splitter

Fair rent by room size, with bills split by days each person was home.

Everything runs inside your browser. Your files never leave your device.

Ask about Rent Splitter

Questions about what this tool does, which option to pick, or what it can and cannot handle.

The question you type here is sent to an AI provider to be answered — your files and whatever you put in the tool above are not, and the assistant cannot see them. Answers are generated and can be wrong. The tool itself is not guessing: it runs deterministic code on your device.

About the Rent Splitter

Splitting rent equally is fair only when the rooms are equal, and in most flats they are not. One room has the balcony and the attached bathroom; another is the box room by the kitchen. Paying the same for both is a small injustice repeated every month, and it is usually the newest flatmate who gets the box room. This rent splitter divides the rent the way most fair-minded flatmates eventually agree on.

The rent is treated as two parts. The share that pays for common space — kitchen, hall, balcony, the corridor everyone walks through — is divided equally, because everyone uses it equally. The rest pays for private space and is divided by room size. Set the common share to whatever your flat agrees; 30% is a common starting point, and 0% splits the whole rent by room size alone.

Room size can be in square feet, square metres or anything else, because only the proportions matter. If the bigger room is better in ways a tape measure misses, give it a weight instead of an area.

Bills are a different question. Electricity, water, internet and the cook's salary follow who was living there, not how big the room is, so they are divided by the number of days each person was home this month. Someone away for twelve days pays for eighteen.

Every figure is worked out in paise and adds back to the rent and the bills exactly. Round each person's payment to the nearest ten and the page says how much over or under the total that leaves, so somebody can absorb the difference knowingly.

How to use it

1Enter the monthly rent and this month's bills.
2Add each flatmate with their room size and the days they were home.
3Set how much of the rent counts as common space, split equally.
4Read off what each person pays, and round it if you like.

Questions

What share of the rent should count as common space?: There is no rule; 25–35% is typical for a flat where the living room and kitchen are generous. A shared room with a small kitchen might use less. Agree on the number once and keep it each month.
Should rent be reduced when someone is away?: Usually not — their room is still theirs. That is why only the bills follow days at home, while rent follows room size. If your flat does reduce rent for absence, use the group expense splitter with shares instead.
Can I use this for a flat with a couple sharing a room?: Yes. Add the couple as one entry for the room-size split, or as two people with half the room each — the result is the same for rent. For bills, two entries counts both of them.