LowercaseOnline — Free Online Text Tools

Security Deposit Interest Calculator

Calculate interest owed on a security deposit based on amount held, dates, and your local interest rate.

Deposit Details
$
%
Important: Interest requirements vary by state and municipality. Many states do not require interest on security deposits. Others specify the rate by law or tie it to a bank rate. Always verify your local requirements before using this tool to calculate what you owe.
State Interest Rate Quick Reference
StateInterest RequirementNotes
CaliforniaNo statewide requirementSome cities (e.g., Los Angeles) may have local rules
New YorkRequired for buildings 6+ unitsRate set by the bank holding the deposit; must be held in interest-bearing account
New JerseyRequiredRate varies — must be held in an interest-bearing account; landlord may keep 1% admin fee
Massachusetts5% per year (or bank rate)Must pay tenant the higher of 5% or actual bank rate annually
ConnecticutRequiredRate tied to savings account rate at the holding bank
IllinoisRequired in certain municipalitiesChicago requires interest based on City Comptroller rate; statewide no universal rule
OhioNo requirementNo statewide rule requiring interest on security deposits
FloridaRequired if deposited in interest-bearing accountLandlord may choose interest-bearing (pay tenant) or surety bond (no interest)

This table is for general reference only and may not reflect current law. Verify with your state's landlord-tenant statutes or a local attorney.

Security Deposit Interest Laws

How Simple Interest Is Calculated

This calculator uses simple interest: Interest = Deposit × Rate × (Days / 365). Simple interest does not compound — it is calculated on the original deposit amount only. Some jurisdictions use slightly different formulas (e.g., monthly compounding or different day-count conventions).

When Must Interest Be Paid?

In states that require interest, landlords typically must pay it at the end of the tenancy when returning the deposit. Some states (like Massachusetts) require annual payment of accrued interest or a credit to the tenant each year.

Penalties for Non-Compliance

Failing to pay required interest — or failing to return a deposit within the required timeframe — can result in the tenant being owed 2–3 times the deposit amount in damages, plus attorney's fees. These penalties vary by state and are strictly enforced in many jurisdictions.

Itemized Deductions

Landlords can generally deduct from the deposit for unpaid rent, cleaning beyond normal wear and tear, and damage caused by the tenant. Normal wear and tear — minor scuffs, small nail holes, carpet wear — cannot be deducted. Provide an itemized statement of deductions within the required deadline (often 14–30 days after move-out).

Best Practices

Hold the deposit in a separate, clearly labeled bank account. Track the deposit date and amount precisely. Document the property condition at move-in and move-out with photos and a signed checklist. Return the deposit (with interest if required) within your state's deadline, even if you have deductions to make.