Rent Split Calculator by Room Size
Each room pays for its own floor space, and everyone pays an equal part of the space you share. Enter the rent and the size of each bedroom: the plan redraws as you type, and the agreement prints on one page.
Tap a room to edit it, or drag the handle on its wall to try a different size.
This is an example flat with made-up names. Put in your rent and your rooms.
Who pays what
Method: By room size
| Room | Share | Rent a month |
|---|---|---|
| Mayaown bathroom | 38% | $903.98 |
| Leobalcony | 33% | $787.54 |
| Priyaparking | 30% | $708.48 |
| Total | 100% | $2,400.00 |
The arithmetic
By room size. The shared space is 380 ft² of 745 ft², 51% of the floor, so 51% of the rent — $1,224.16 — is split evenly: $408.05 for each of 3 people.
The other $1,175.84 is split between the rooms by weighted size, 409 ft² in all: $2.87 per ft².
Weighted size is a room's size made larger by its extras (own bathroom +15%, balcony +10%, parking +10%).
Each amount is rounded to the cent, and the rows add up to the rent exactly.
The agreement
This sheet is what prints: the split, the method, the arithmetic and a line for each of you to sign.
Rent split agreement
Our home
Monthly rent $2,400.00, split between 3 people. Method: By room size
| Name | Room | Extras | Share | Pays a month |
|---|---|---|---|---|
| Maya | 150 ft² | own bathroom +15% | 38% | $903.98 |
| Leo | 120 ft² | balcony +10% | 33% | $787.54 |
| Priya | 95 ft² | parking +10% | 30% | $708.48 |
| Total | 100% | $2,400.00 |
By room size. The shared space is 380 ft² of 745 ft², 51% of the floor, so 51% of the rent — $1,224.16 — is split evenly: $408.05 for each of 3 people.
The other $1,175.84 is split between the rooms by weighted size, 409 ft² in all: $2.87 per ft².
Weighted size is a room's size made larger by its extras (own bathroom +15%, balcony +10%, parking +10%).
Each amount is rounded to the cent, and the rows add up to the rent exactly.
We agree to pay the monthly rent in the shares above. We will look at the split again if anybody moves in or out, a room changes hands, or the rent changes.
Name Maya
Signature
Date
Name Leo
Signature
Date
Name Priya
Signature
Date
This sheet records how the people who sign it have agreed to divide the rent among themselves. It is not a lease and not legal advice, and it does not change what any of us owes the landlord.
Worked out with the rent split calculator at gethomsy.com
Prints on one page, A4 or Letter
The rent is settled once; the chores and the shopping come round every week. The best apps for roommates covers which app does which job.
What you enter is saved in this browser and in the share link. There is no account.
How the rent split is calculated
Every room gets a weighted size: its floor area, made larger by the extras it has — by default 15% for a private bathroom and 10% each for a balcony and a parking space. Those three percentages are our own round starting numbers for a conversation, not market rates, and the page lets you change each one. The rent is then cut into two parts. The equal part is split evenly between every person in the house. The size part is split between the rooms in proportion to their weighted sizes, and a room with two or three people in it divides its own slice between them.
The two methods differ only in how big the equal part is. By room size, it is the shared space's share of the whole floor: 380 ft² shared beside 365 ft² of bedrooms puts 51% of the rent in the equal part. With no shared space entered, the whole rent follows the rooms. Equal base plus size premium uses a percentage you set, 50% to start, whatever the floor looks like. The results table shows each room under both methods.
Every amount is rounded to the cent per person by the largest-remainder rule, so the rows add up to the rent exactly. The unit switch converts sizes at 10.7639 square feet to the square metre and rounds each to one decimal. Only the sizes relative to each other matter, so the unit itself changes no amount; the rounding of a converted size can move one slightly. The floor plan is drawn to the sizes entered — each row as tall as its rooms' share of the floor, each room as wide as its share of its row, the shared band at its share of the floor but never thinner than its label or taller than two fifths of the plan — which makes it a picture of proportions rather than of your real layout. The example flat and its names are ours. Nothing here is legal advice, and the printed agreement is not a lease.
Every figure above was read out of the code that runs on this page. Where a number is our own judgement rather than a published one, the note says so and cites nothing. Method last checked 28 September 2026.
Why a rent split by room size is worth writing down
Most shared houses start on an even split because it is the only number nobody has to defend. It lasts until somebody notices that the biggest bedroom has its own bathroom and the smallest one fits a single bed and a chair, and then the conversation happens anyway — usually later, and usually worse. A split by room size is not about the money so much as about having a reason: a number anybody in the house can work out again from the sizes, instead of one that was agreed on a moving day and never mentioned again.
The arithmetic is short. Everybody uses the kitchen, the living room and the hall the same, so that part of the rent is split evenly; the bedrooms are what differ, so the rest follows them. The two methods here disagree only about how big the even part should be — the share of the floor you all use, or a percentage you pick — and the table prints both answers side by side, so the choice is between two numbers you can see. The extras are where most houses argue: a private bathroom, a balcony, a parking space. Nobody publishes a price for them, and this page does not invent one. It counts each extra as a bigger room by a percentage the house agrees, and prints that percentage on the sheet so it is part of the agreement rather than a memory.
Write the result down. The printed sheet carries the rent, the method, the arithmetic and a line for each of you to sign, and it belongs next to the rest of the house rules — our roommate agreement generator covers the other eight topics, from quiet hours to moving out. Rent is also only the largest bill: the household bills calculator totals the rest of the fixed costs, and splitting household expenses with roommates covers the groceries and the supplies that no floor plan can divide. If the house earns very different amounts, the expense fairness calculator splits bills by income instead.
The honest limit of any split is that it is agreed once and lived every day. The money is the easy part to settle. The chores are the part that comes round every week, and the best apps for roommates covers which app does which job — the chores, the bills and the shopping list — because no single one does all three.
Frequently Asked Questions
How do you split rent by room size?
What is the fairest way to split rent between roommates?
How much more should the person with the private bathroom pay?
How do you count shared space like the living room and kitchen?
What does equal base plus size premium mean?
How do you split rent when a couple shares a room?
Can I use square feet or square metres?
Is the printed agreement a legal contract?
Does the page save what I entered?
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The rent is settled once. Chores, the shopping list and the house calendar come round every week: Homsy gives each chore a named owner and a rotation, keeps one shopping list everybody adds to, and shows who is away.