Rent Split Calculator

Splitting rent evenly is easy. Splitting it fairly, once the rooms or the incomes stop matching, is where the arguments start. There's no outside data to look up here. It's arithmetic on numbers you already have: the rent, and either nothing else, everyone's income, or everyone's room size.

• Equal split divides the rent evenly, regardless of income or room.
• By income gives each person the share of rent that matches their share of the combined income.
• By room size gives each person the share that matches their private room's square footage.

Add roommates with the "Add another roommate" button, up to eight, drop back to two with "Remove," and every share recalculates as you type.

There is no single "correct" way to split rent. The right method is whichever one your household agrees reflects what you actually value, equal contribution, ability to pay, or private space received.

If you've seen the New York Times rent-split calculator, this one works differently. The NYT tool runs an iterative "envy-free" algorithm built on Sperner's Lemma from fair-division math, pricing each room against each roommate's preferences until nobody would rather swap.^[2] This rent split calculator keeps to the direct, proportional methods most people are actually looking for, split evenly, by income, or by room size, and skips the back-and-forth. Whichever you pick, the shares total exactly 100% of the rent you entered.

All three are one click apart. The table is the short version; the rest of this is how to read it.

Equal split is the one to reach for when the rooms are close in size, the incomes are in the same range, or you're a couple pooling finances anyway. It's the easiest to agree on and the easiest to explain to whoever moves in next. Go with the income split instead when earnings differ enough that tying rent to the room feels off, and the household would rather tie it to ability to pay. That's common between roommates, rare between couples sharing a bank account. Room size wins when one bedroom is clearly bigger or comes with an en-suite or a wall of closet, and people want to pay for what they actually get rather than what they earn.

When a household can't agree, equal is the safe default, worth moving off only if someone genuinely feels shortchanged. The switch tends to happen once, early on, so it pays to have the conversation up front rather than relitigate it every few months.

A split only holds if everyone signs off before move-in. Pick the method first, equal, income, or room size, so the talk is about fairness and not whichever figure favors someone; the income method means being open about earnings, and if that's a non-starter, room size or an equal split sidesteps it. Write the agreed number down with the date, send everyone the share link so they're on the same figures, and keep utilities on their own tab, usually split evenly.

Real apartments rarely have matching rooms and matching paychecks, so small adjustments are normal: a flat $50-$100 premium for an en-suite before the rest is split by size, a small equal base before the remainder runs through the income method, a discount for a room on a noisy street. Agree the exact amount and the reason in writing so it isn't a fresh argument at renewal. Most disputes trace back to skipping that step, defaulting to an even split nobody really agreed to, leaving an obvious room difference until someone complains, or mixing methods (rent by size, utilities by income) without saying so.

Once you know your own share, check it against the federal affordability line, a household is "cost burdened" above 30% of gross income.^[1] The Rent Budget Calculator runs that against your income, and if a roommate falls behind, the Emergency Fund Calculator covers the month you front their share.