Rental Calculators — Deposit Interest & Rent Increase
All free calculators: security deposit interest by state, rent increase caps and notice rules. Statute-based, no signup, runs in your browser.
Quick answer
Two free tools, both driven by state law: the security deposit interest calculator applies your state's statutory rate to your deposit; the rent increase calculator shows the maximum legal increase where your state caps rent — and the notice rules where it doesn't. Every rule traces to a statute cited on the state pages.
The calculators
| Calculator | What it answers | State rules applied |
|---|---|---|
| Security deposit interest | How much interest does my landlord owe on my deposit? | Rate, compounding, payment timing — all 50 states + DC |
| Rent increase | What is the maximum legal rent increase? | Cap formula in capped states; notice rules in uncapped states |
Both calculators run entirely in your browser. Nothing you enter is uploaded or stored.
Where the rules come from
Each calculator is a front end for the state pages: deposit interest by state covers the interest requirement — which states mandate it, the current rate, and the statute — and rent increase by state covers caps, formulas, exemptions and notice requirements. When a state law changes, the state page's Last Verified date moves and the calculator inherits the update.
State statute (official text) · 2026-10-28How to choose the right calculator
Start from the question you actually need answered:
- "How much interest has built up on my deposit?" → the security deposit interest calculator. You will need your deposit amount, the date you moved in, and either your move-out date or "ongoing". The state selector applies your state's rate automatically — you never have to look the rate up yourself.
- "Can my landlord raise the rent this much?" → the rent increase calculator. Enter your current rent and, optionally, the proposed increase percentage. In capped states you get the legal maximum and a verdict on the proposal; in uncapped states you get the notice rules that actually protect you.
Both tools then link you to the underlying state pages — deposit interest by state and rent increase rules by state — where the full rule text, eligibility conditions and statute citations live. The calculator is the quick answer; the state page is the evidence.
FAQ
Do the calculators store what I enter?
No. All math runs in your browser; nothing is transmitted or logged. See the privacy policy.
Why does my state's result show no number?
Honesty first: if your state has no statewide interest requirement, or pegs the rate to a benchmark whose current value we have not verified against the official announcement, the calculator says so instead of inventing a figure. The state page always links where the official number publishes.
Are the calculators free?
Yes — no signup, no paywall, no limits. The site is supported by advertising.
Estimates only — nothing on this site is legal advice (see the disclaimer).