Rent Split Calculator
Fair rent shares by room size, income or equality, with the working shown. 100% free, no signup. Everything runs in your browser.
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Every shared home has the conversation, and most have it badly: the big room's occupant defends equal splits, the box room simmers, and fairness gets negotiated by personality instead of arithmetic. The fix is picking a method in the open. Three exist, each fair by a different philosophy: equal shares, the simplest; by room size, where private space is what you buy; by income, where the household shares burden proportionally. This calculator runs all three with the working shown.
Enter the rent and the people; for the size method, bedroom areas; for income, honest incomes. Shares and percentages come back, visibly derived, and the argument changes from 'you always' to 'which method do we pick', which is a conversation adults can finish. The notes handle the classic refinements: private bathrooms, shared space, and who absorbs the rounding unit.
How to use
- Enter the total rent.
- Pick the method: room size, income, or equal.
- List the flatmates, with room areas or incomes as the method needs.
- Read each share and its percentage of the total.
- Adjust by open agreement for extras: a private bathroom or balcony is worth a few nudged percent.
- Screenshot the table into the house chat, and let the method, not the loudest voice, be the answer.
Why use our rent split calculator?
The size method's logic holds up under argument, which is what a method is for: shared spaces serve everyone equally and split equally, private space differs and is what the differing payments buy. Counting only bedroom areas implements exactly that, and the percentage column shows the fairness working: the 16-square-metre room pays its share of the private-space pie, not a punitive premium invented in the kitchen at midnight. The income method serves the different philosophy families and couples often quietly hold, that a home should cost each member a similar fraction of their means, and putting a calculator behind it makes the income-sharing conversation possible at all.
The refinements live in the notes because rigid formulas lose to real homes: a private bathroom is worth a few percentage points by agreement, a windowless room less, a garden-access room more, all easier to negotiate once the baseline exists. Rounding leaves a unit or two loose and tradition assigns it to the biggest room, a rule whose pettiness is precisely its charm. The budget calculator helps each person place their share inside their own finances, and the percentage calculator handles the ad-hoc adjustments the house invents next.
One social effect repeats wherever this tool gets used: the argument ends not because everyone agrees philosophically but because the numbers are visibly derived from a method everyone accepted in advance. Fairness disputes are mostly disputes about hidden reasoning, and a table with percentages showing its work removes the hiding place. The house that picks its method before moving in has, in one conversation, prevented a year of small resentments.
Who is this tool for?
New house-shares settle the shares before anyone unpacks, which is the cheapest possible timing for this conversation. Existing houses re-run it when someone swaps rooms or a rent rise lands, since a change is the natural moment to fix an old inequity without relitigating history.
Couples with different incomes use the income method for the whole home, one of those arrangements many run and few discuss; the calculator gives it numbers and normality. Landlords renting by the room sanity-check their per-room pricing against area. And the group's spreadsheet person, finally relieved of defending their formula, just sends the link.
Frequently asked questions
Each is fair by a philosophy: equal is simplest, size prices the private space you actually get, income equalizes burden. Fairness is the household agreeing on the philosophy; the calculator's job is making each one's numbers visible so the choice is real.
No: shared space serves everyone and is effectively split equally inside every method. Count private bedroom areas only for the size method. A room hoarding the balcony or an ensuite gets a negotiated nudge, not a remeasured formula.
Any consistent way: meters with a phone app or tape, or even paces, since only the proportions matter. Measure once together, agree the numbers, and the method survives every future rent change automatically.
Rounding to whole units leaves a unit or two adrift. Convention assigns it to the largest room or rotates it monthly; either way, deciding once ends it. The percentages are exact; money just refuses decimals politely.
The couple's room is one room by size, but two people use the shared spaces, so many houses split rent into a private-space part by area and a shared part by headcount. Run the size method, then shift an agreed amount from singles to the couple for the shared-space difference; the baseline makes the negotiation short.
No. Everything computes in your browser and vanishes with the tab, which for the income method is the entire condition of the conversation happening.
Convention splits them equally regardless of room size, since usage does not follow floor area, though income-method households often apply their ratio to everything. Decide once, write it in the house chat, and let the method answer the monthly question.