Split rent and bills between housemates

An even split looks like the fair default. It is only fair when the rooms are interchangeable, and they almost never are: one has the en-suite, one is above the kitchen, one is a box room that fits a bed and a resentment.

Dividing by floor area is the usual next step, and it is better. It is also a proxy that ignores everything people actually care about — the morning light, the noise from the road, being next to the bathroom or next to the bins. Two rooms of identical area are routinely worth twenty pounds a month apart to everybody in the house, and a measurement cannot see that.

So the third option on this page asks the question directly: what is each room worth to each of you? Everybody fills in their own row, ideally without looking at anybody else's, and the page works out both who gets which room and what each room costs.

The prices this page produces have two properties, and they are the whole claim.

They add up to exactly the rent. Every penny of it, every time, however awkwardly it divides.

And at those prices, no housemate would rather have somebody else's room at somebody else's price. Not "everybody is delighted" — the box room is still the box room, and whoever takes it may still wish they had the loft. What is true is that they would not swap: at £120 less a month, the box room is a deal they prefer to the loft at its price. There is no trade left on the table, which means there is nowhere for the argument to go.

That is a real guarantee rather than a slogan, and it is checked rather than assumed. Two things make it possible. First, the rooms go to the people who want them most, measured by everybody's own numbers — if some swap would make the group better off by its own account, then at *any* prices one of those two people would rather have the other's room, and no price list could settle it. Second, once the rooms are handed out that way, prices with the no-swap property always exist, and the page finds them.

Your numbers do not have to be in the same units as anybody else's. Split the rent across the rooms, use percentages, or score them out of ten — each row is scaled against itself before anything is compared, so nobody's opinion counts for more because they wrote bigger numbers.

A couple in the double is one line on this page, not two, with the people in it set to 2. Which raises the question the page has to answer: should they pay less?

Per person, yes. Together, no.

The rent is buying two different things, and they behave differently. **The room** is one room whether one or two people sleep in it — so its price is split between them, and each pays about half what a single person pays for a comparable room. That is the whole point of sharing one. **The rest of the house** is not: the kitchen, the bathroom queue, the sofa, the hot water and the wear are used per person, and two people use two people's worth.

So a couple should pay more than that room alone would cost, and each of them should still pay less than somebody with a room to themselves. Charge purely by the room and everybody else is quietly carrying two people's share of the kitchen. Charge purely by the head and the couple is paying a premium for having *less* space each, which is the opposite of the deal they took.

The page splits the difference the way most house shares settle it: a second person in a room counts as **half a housemate** for everything that is not the room. On £2,000 between four rooms with one couple, that is £666.67 for the two of them — £333.34 and £333.33 — against £444.44 for each of the three singles, one of whom pays the spare penny. The couple pays more than a room and less than two; each of them pays less than anybody with a room alone; and it still adds up to exactly £2,000.

If your house disagrees, the setting is right there: a second person can count for nothing (just the room, split between them) or as a whole housemate (five people in the house, five shares). Those are the two ends of the same argument, and both are defensible — the page just refuses to pick one silently.

One thing it does not split in half: a bill that divides evenly divides between **people**, not rooms. Nobody uses less broadband for sharing a bedroom.

Bills go on top of the rent and split one of two ways.

Evenly is right for anything the house consumes as a house: broadband, the licence, the window cleaner. Nobody uses less broadband by having a smaller room.

In the same ratio as the rent is right for anything the building consumes, because the ratio is already a decent proxy for it. Heating a big room costs more than heating a small one, and if the rent ratio says 40/35/25 then so, roughly, does the radiator.

What does not belong here is the one-off that only some of you owe — the taxi, the shared shop, the round of drinks somebody covered. Those are expenses rather than bills: they happen once, they involve different subsets of people every time, and they need settling up rather than dividing. The expense splitter is the page for those, and the two are meant to be used side by side: this one for the standing numbers, that one for the month's receipts.

If somebody arrives on the 9th, they do not owe the whole month. Put the days they are actually there in the "days there" column and their first-month figure appears beside their monthly one.

The days nobody was there are deliberately *not* spread across everybody else, and this is the decision most likely to come up. Those eight days are not the other housemates' to cover: they did not get the room, and it was not their gap. Either the person who moved out owes them, or the room stood empty and whoever signed the lease is carrying it. A tool that quietly reallocates them produces a number the house then argues about — and the argument is correct, which is the worst kind.

So the monthly shares stay the answer to "what does this cost every month", every one of them still adds up to the rent exactly, and the part-month figures sit beside them as what to transfer for this month only.

Eighteen hundred pounds three ways is not three equal shares, and neither is a £45 broadband bill. Somebody pays the extra penny.

This page hands the remainder out rather than rounding it away: every share is the exact floor of the division, and the leftover pennies go one each to the people with the largest fractional claim on them. The shares of every bill add up to that bill, always, and the rent shares add up to the rent — which is why you can add the column up by hand and have it come out right.

The room pricing has a subtler version of the same problem, and it is the one place this page will tell you it cannot be exact. Room prices can only move together — raising one by a penny and not the others is what would create the first bit of envy — so the total moves in steps of one penny per room. Occasionally the rent is not reachable in those steps, and the page says the prices are within a penny of the fair set rather than pretending otherwise. Nudging one bid by a pound resolves it. In practice you will not see this: it needs numbers so tied that everybody values everything identically.

For working out the numbers, one sheet is fine, and it is why this page is a free tool rather than a signup form. The rent does not change every month. You settle the split once when somebody moves, print it, and it is done.

It stops being fine at the point where the question changes from "what does each of us owe" to "who has actually paid". That is not arithmetic, it is a record: a row per person per month, kept somewhere all of you can see, that still says what happened in March when somebody queries it in June. A link in one person's browser cannot be that, and the person keeping it ends up as the house's accounts department — the same unpaid, invisible job the expense splitter's copy describes, except that this one repeats every month for years.

You have outgrown this page when you notice you are the only one who knows whether this month is settled, you are chasing the same two people every month, and somebody has started disputing a bill from the spring that you cannot evidence.

That is the job the Expense Splitter app does. Everyone sees the same ledger, bills recur without being retyped, a payment between two people is something both sides sign off, and the record of what was agreed survives the disagreement about it.

• Expense Splitter
• Chores & Allowance
• Maintenance

Every app in the library is included with the household plan. This page stays free either way.

• How to share the mental load at home, not just the chores
• Seven questions to ask any family app before you put your household in it
• Split shared expenses and see who pays who
• Work out what your subscriptions really cost in a year
• Make a printable chore chart for your family
• Name the invisible work, then see who is actually holding it
• A home maintenance checklist for your house, grouped by season