Rent split calculator: fair shares by room size, income or head count
Splitting rent evenly is simple, but it is rarely fair when one roommate has the master bedroom with its own bathroom and another has a box room. This rent split calculator divides the rent three ways: by room size (square footage or square metres), by income, or equally per person. You can add a premium for a private bathroom or a parking space, and share the kitchen and living room across the rooms.
It works for flatmates, for a house share, and for couples: set “people in the room” to 2 for an equal split, or enter the pair’s combined income for an income split. A side-by-side table shows what each person pays under all three methods, so you can see the trade-off before you agree. It is not the same as a bill splitter: for a restaurant tab or shared expenses, use the split bill calculator.
How to use the Rent Split Calculator (by room size or income)
- Choose your Country, enter the total rent and the number of people.
- Pick how to split: room size, income or equal per person.
- For each person enter a name, room area and income. Tick private bathroom or parking where it applies.
- Set the bathroom and parking extras and any shared area, then read the shares.
- Use Copy the split to paste the result into your group chat.
Rent Split Calculator (by room size or income) features
Three methods
Room size, income or equal per person, with a comparison table.
Amenity extras
A private bathroom or parking space is charged to its user before the rest is shared.
Shared space
Spread kitchen and living areas across the rooms when splitting by size.
Couples
Count two people in one room, or use combined income.
Share of income
See what percentage of income each person pays.
How each method works
First the extras are taken out: rent to split = total rent − bathroom extras − parking extras. Each person then pays rent to split × their weight ÷ total of all weights, plus their own extras. The weight is room area (plus an equal part of any shared area), income, or head count.
Example: a $2,400 rent for three rooms of 200, 150 and 150 sq ft gives $960, $720 and $720. By income (5,000, 4,000 and 3,000 a month) the shares are $1,000, $800 and $600, so everyone pays 20% of income. Equally, it is $800 each. If the first room has a private bathroom worth $100, $2,300 is split by area ($920, $690, $690) and the first person adds $100 to pay $1,020.
| Method | Best when | Watch out for |
|---|---|---|
| Room size | Rooms differ a lot in size | Ignores light, noise and storage |
| Income | Earnings differ widely | Needs honesty about income |
| Equal | Rooms and incomes are similar | Can feel unfair to the smallest room |
Tips and limits
- The extras are your own estimates of what a bathroom or parking space is worth. Agree them before you move in.
- Use the same period for rent and income (both monthly, or both weekly).
- Most leases make every named tenant liable for the full rent. Your split is an agreement between you, not with the landlord.
- To find out how much rent your own income supports, see the rent affordability calculator.
Rent Split Calculator (by room size or income) FAQ
How do you split rent by room size?
Divide each room’s area by the total area of all rooms and multiply by the rent. Equal rooms pay equal shares; a room 10% bigger pays about 10% more.
How do you split rent by income?
Divide each person’s income by the combined income and multiply by the rent. Everyone then pays the same percentage of their income.
How should a couple split rent with a roommate?
Either count the couple as two people in an equal split, or give them one room share and combine their incomes for an income split. The tool supports both.
Should the shared areas count?
Many flatmates share the kitchen and living room equally, so enter their total area as shared area. It is divided between the rooms.
How much extra should a private bathroom cost?
There is no fixed figure. Roommates commonly agree on a flat sum or a few percent of the rent. The tool lets you enter any amount.
Is this legal or financial advice?
No. It is a calculator to help friends agree a split. Check your lease, because each tenant is usually liable for the full rent.