Free tool · 2026
Security Deposit Interest Calculator
Work out the interest a landlord owes on a security deposit in states that require it. Enter the deposit, the dates it was held, and the rate — the statutory rate is prefilled where one is fixed, and editable everywhere else so your result is never based on a stale number.
This state's rate is tied to a bank/treasury index and changes over time — enter the current rate.
Interest owed (simple)
$0.00
Enter the move-in date
- Deposit
- $1,500.00
- + Simple interest
- $0.00
- Total to return
- $1,500.00
Rates for most states change yearly and are tied to bank or treasury indices. Always confirm the current rate before relying on this figure.
How security deposit interest works
A number of states require landlords to hold security deposits in a way that earns interest and to pay that interest to the tenant — either annually or when the deposit is returned. The mechanics vary: some states set a fixed rate in the statute, while most tie it to a bank passbook rate or a U.S. Treasury index that is republished each year. That's exactly why a calculator with a hardcoded rate tends to be wrong within a year — this one prefills a rate only where it's genuinely fixed and otherwise asks you for the current figure.
Most statutes specify simple interest (deposit × rate × years). We show a compound figure alongside it only for comparison. For the precise rule and rate in your state, open your state's page:
Security deposit interest FAQ
Which states require interest on security deposits?
9 states plus the District of Columbia require landlords to pay interest on held security deposits, including Connecticut, District of Columbia, Maryland, Massachusetts, Minnesota, New Jersey, and others. Each state's rule and rate differ.
How is security deposit interest calculated?
Most states use simple interest: deposit × annual rate × number of years held. A few reference the rate actually earned in the account instead. This calculator shows both simple and (for comparison) compound interest, and lets you enter the exact current rate for your state.
Why does this calculator let me enter the rate myself?
Because in most states the required rate is tied to a bank or U.S. Treasury index and changes every year — a hardcoded rate quickly becomes wrong. Where a fixed statutory rate exists (e.g., Massachusetts and Ohio at 5%), it is prefilled; otherwise you enter the current figure so the result is accurate.
Calculating a full refund? Use the security deposit calculator →
Landlord Tools provides self-help templates and general information, not legal advice, and is not a law firm. Using this tool does not create an attorney-client relationship and does not guarantee any outcome. Landlord-tenant rules vary by state and locality and change over time — confirm your current requirements with the applicable statute or a licensed attorney before relying on any result.