Security Deposit Interest Calculator
Calculate the interest owed on a rental security deposit between two dates at your state, city or bank rate, minus any administrative fee and deductions.
In some states and cities, a landlord who holds a security deposit must pay the tenant interest on it, either at a rate fixed by law or at whatever the bank account earns. Rules differ on the rate, on fees the landlord may keep and on whether interest is paid yearly or at move-out. Enter the rate that applies to you and the dates, and this calculator works out the interest and the refund.
How to use this tool
- Enter the deposit amount and the yearly interest rate that applies.
- Enter the date you paid the deposit and the date it is returned.
- Choose simple interest, or compounding on each anniversary if interest stays in the account.
- Add any administrative fee your state allows the landlord to keep.
- Enter deductions for damage or unpaid rent to see the final refund.
Formula
Simple before fees: I = D × r × t
Compound before fees: I = D × (1 + r)^n × (1 + r × d ÷ 365) − D
D is principal, r the gross annual rate, t deposit years plus stub days/365, n whole years and d remaining days. Each period deducts the fee on original principal, capped at earned interest; compound mode reinvests the balance.
Example
A $2,000 deposit paid on 1 September 2024 and returned on 15 December 2026 at 1.5% a year is held 835 days: two whole deposit years plus 105 days. With simple interest the tenant is owed $30 + $30 + $8.63 = $68.63. If interest compounds on each anniversary, the second year earns $30.45 and the last 105 days $8.89, for $69.34 and a refund of $2,069.34 before any deductions.
Frequently asked questions
Do all landlords have to pay interest on deposits?
No. Many states have no interest requirement at all. Where one exists it may cover only certain buildings or cities, so look up your state statute or city housing office.
What is the 1% administrative fee in New York?
New York General Obligations Law § 7-103 lets a landlord who keeps the deposit in an interest-bearing bank account retain 1% a year of the deposit for administration. The rest of the interest belongs to the tenant.
Can deductions be taken from the interest too?
Lawful deductions are usually taken from the total the landlord holds, deposit plus interest. Many states require an itemized list of deductions within a set number of days after move-out.
Sources
This tool gives an estimate for general information only. It is not financial, tax, legal or medical advice — check with a qualified professional before you rely on the result.
Last updated: 2026-10-30