Money math,
split fairly.
Calculators for the money questions that come with sharing a home: who pays what, and what a partial month costs.
Calculators
What is Money Vault?
Money Vault is a small set of free calculators for renters, roommates and anyone sharing costs. Each one shows how it gets the answer, so your whole group can check the numbers and agree on them, and Copy summary turns the result into a list you can paste into a group chat.
The calculators run in your browser: what you type isn't saved or sent anywhere, and there's nothing to sign up for.
Which calculator do you need?
Moving in with roommates? The Rent Split Calculator works out each room's share, whether the rooms are different sizes, a couple shares a room or one room has its own bathroom. Moving in or out in the middle of a month? The Prorated Rent Calculator works out the rent for just the days you have the place.
Frequently asked questions
Is Money Vault free?
Yes. Both calculators are free, with no sign-up, no account and no limits.
Do the calculators give legal or financial advice?
No. They do the arithmetic for the method you choose. Your lease, and what your group agrees, decide what anyone actually owes.
Does Money Vault store what I enter?
No. Everything is worked out in your browser, and closing the page clears it.