A free, zero-login rent split calculator that produces fair, mathematically defensible splits for roommates — accounting for room size, bathrooms, and parking.
Splitting rent equally sounds fair until you realize one roommate has an ensuite bathroom and a parking spot and the other has a closet-sized room next to the laundry. Equal splits ignore what each room actually offers.
RoomTally was built to solve a real problem: how do you split rent in a way that every roommate can look at and say "yes, that's fair"? The answer is a weighted algorithm that accounts for what each room is actually worth — not just how many people are paying.
The result is an envy-free split, a concept from fair division theory meaning no roommate would prefer to swap rooms and payments with anyone else. RoomTally makes that math accessible to anyone moving into a shared home.
Your total rent is divided into two equal pools. The first half is split equally among all roommates — your share of common areas. The second half is split by room size — the bigger your private space, the more you contribute.
From there, amenity adjustments are applied using zero-sum logic. An ensuite bathroom adds a premium to that room and distributes an equivalent discount across the others. A guest-accessible bathroom — one that other roommates or visitors pass through — earns a discount instead. Parking works the same way.
Every dollar of premium is offset by a dollar of discount elsewhere. The total always equals your rent exactly.
RoomTally doesn't ask for an account. It doesn't store your information. Your entire configuration lives in a URL that you can bookmark, share with roommates, or return to each month to update utility costs.
The tool works entirely in your browser. Nothing is sent to a server. When you share your link, your roommates see exactly what you see — the same numbers, the same breakdown, calculated fresh on their device.
Wilde DataLabs is an independent software studio building practical tools for everyday problems. RoomTally is our first consumer product. We're focused on building things that are useful, honest, and designed to respect the people using them.
We don't sell your data. We don't run dark patterns. We build tools we'd want to use ourselves.
Ready to split rent fairly?
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