How the rent split calculator works
Enter the total rent and each room's size. The first column shows rent split in proportion to size. The second column adds your extras: a positive number for a room with a private bathroom or balcony, a negative number for a room with less light or no window. The other rooms share the difference, so the total never changes.
A worked example
A £2,400 flat has three rooms of 18, 14 and 12 square metres (44 in total). By size alone, the rooms pay £818.18, £636.36 and £545.45. If the biggest room has an ensuite worth £150 more and the smallest has no window worth £150 less, the extras move the figures by those amounts, and the other rooms absorb the small difference in proportion to their size.
Which method is fair?
Size is simple and easy to defend. Extras reflect what people actually care about. A points system (score size, light, noise and bathroom, then divide by points) is a third option, covered in the guide below. Agree the method before anyone signs.
Related guide: How to split rent fairly when rooms differ
Frequently asked questions
Should shared rooms count?
Usually the kitchen and living room are shared equally, so leave them out of the room sizes and split only the private rooms, or treat the whole rent as the pool.
Does this include bills?
No. This is for rent. Utilities are normally split equally or by days of occupancy.
What are fair extras?
Whatever the group agrees. A private bathroom or balcony is often worth a noticeable amount; a small window is worth less. Write the numbers down.
Is anything saved?
No. Everything stays in your browser.