You get paid on the 15th and the 30th. Rent is due on the 1st, the car on the 8th, and the daycare invoice whenever they feel like sending it. How much of Friday’s paycheck should go to which account?
Budget Allocator answers that. List what comes in and what has to go out, and it tells you exactly how much to move from each paycheck to each bill.
How to use it
- Enter your income. Each paycheck, rental payment, or side income as its own line, with what it brings in per month.
- Enter your costs. Rent, groceries, childcare, savings — anything you fund every month.
- Mark what’s reliable and what’s non-negotiable. Salary is Guaranteed; freelance is Varies. The mortgage is Must pay; the travel fund is Nice to have.
- Read the table. Each row is a source, each column a bill, and each cell is the transfer to make on payday.
That’s the whole thing. It takes about two minutes with a bank statement open.
What you get back
A grid of transfers you can act on directly — move $1,732 from the paycheck to the mortgage account, $892 to groceries, and so on. Row totals confirm every dollar of that paycheck is assigned. Column totals confirm every bill is covered.
Reliable income lands on the bills you cannot miss. Unpredictable income funds the things that can slip. That happens automatically once you mark which is which — it is the whole reason to bother marking them.
If your income does not cover your costs, it says so and tells you by how much, then spreads the gap proportionally rather than fully funding the first few lines and leaving the rest at zero. If you have money left over, it says that too, so you can point it somewhere deliberate.
Take the spreadsheet with you
Download Excel gives you a workbook that still works. Not a picture of today’s numbers — the calculation itself, as live formulas. Change a paycheck amount on the Inputs sheet and every transfer rebalances, with no app and no internet.
That matters if you want to argue with the plan on a plane, hand it to a partner, or keep a copy that will still make sense in two years when this website may not exist.
Why not just fill each bucket in order?
Because it drains one paycheck completely before touching the next, which is not how a month works. Your Friday deposit does not go entirely to rent; it covers most of rent and some of groceries.
Filling buckets in priority order also gets brittle the moment you add a rule — an account that needs a fixed amount, income that should never fund a particular category. There is nowhere to put that.
So this solves the whole grid at once instead, using a technique called iterative proportional fitting: scale the rows until each source is fully assigned, scale the columns until each bill is fully funded, repeat until both hold. It settles in about fifteen rounds and never produces a negative transfer.
Your numbers stay yours
There is no account and no server. Everything runs in your browser and saves to that browser only. Your income and your bills are not data that should have to sit on someone else’s machine so a bit of arithmetic can happen.
The source is public, and the spreadsheet is generated on your device too.