← Security deposit refund & prorated rent calculator
A lot of landlords and tenants already reach for a spreadsheet at move-out: one column for each deduction, a subtotal, a formula that subtracts it from the deposit. That arithmetic is trivial and a spreadsheet does it fine. What it does not do on its own is flag the mistakes that actually cause disputes: an unlabeled deduction, a balance that has quietly gone negative, an interest formula entered once and never rechecked, or a statement that drifted from the sheet because it was retyped into an email by hand.
| Question | Where to answer it |
|---|---|
| What's the deposit minus the deductions? | Either one — a spreadsheet subtracts fine. |
| Did I forget to describe one of the deduction line items? | This calculator — flags any deduction with no description before you send it. |
| Do the deductions exceed the deposit — is this a refund or a balance owed? | This calculator — labels the result explicitly rather than leaving a negative cell to interpret. |
| My jurisdiction requires deposit interest. What's the prorated amount? | This calculator — enter the rate and days held; a rate with no days (or the reverse) is flagged instead of silently returning zero. |
| Can I send the other party a statement that can't drift from my own numbers? | This calculator — the copy button builds the statement from the settlement already on screen, and disables itself if you edit an input without recalculating. |
| Is anything I enter uploaded anywhere? | No, on either — but this calculator needs no account, no template, and no formula to maintain. |
This tool needs no account and nothing installed: it is a static page, the arithmetic runs in your browser, and the deposit amount, every deduction, and every rent figure you enter stay on this device — nothing is uploaded anywhere.
The subtraction is trivial and a spreadsheet does it fine. What a plain spreadsheet does not do on its own is flag a deduction with no description, catch the case where deductions exceed the deposit (a balance owed, not a refund), or keep the copy you send the other party from silently drifting away from the number your own sheet shows — because that copy usually gets retyped by hand into an email.
Interest is deposit times the jurisdiction's annual rate times days held over 365, and every deposit calculator or landlord's own sheet has to encode that formula once and then trust it every time a rate or a day count changes. Enter a rate with no day count, or a day count with no rate, and a spreadsheet cell just returns zero with no explanation — this calculator flags that combination explicitly instead of returning a silent zero.
The statement is generated from the exact settlement figures already on screen, not retyped from them. Editing a deduction after calculating, without recalculating, disables the copy button rather than handing out a statement that disagrees with the table above it — a spreadsheet-to-email copy has no equivalent safeguard, because the retype is a separate, unchecked step.
No. A spreadsheet or ledger that tracks every tenant, every deposit, and every move-out date over years is still the right tool for that ongoing record. This page answers one settlement at a time — what does this deposit refund to, or what does this partial month prorate to — and nothing it computes is saved anywhere once you leave the page.