Security Deposit Calculator

Security deposit rules -- how many months of rent a landlord can collect, and whether interest must be paid on the amount held -- are set entirely by state (and sometimes city) law, and they vary widely: some states cap deposits at one month's rent, others allow two or three, and some impose no cap at all, while interest-on-deposit requirements exist in only a subset of states and typically apply only above a minimum holding period. This calculator does not assume a single nationwide rule; Max Months Allowed and Required Interest Rate are both inputs you set to match your own state's actual statute, and the calculator simply applies whatever limit and rate you enter. Base Deposit is Monthly Rent times Max Months Allowed, and Total Deposit adds Pet Deposit and Furnished Premium on top (where a state or lease permits those additional charges).

Interest Owed applies Required Interest Rate as simple interest over Holding Period, and Total Return Amount is what the tenant should receive back at move-out -- Total Deposit plus any Interest Owed, before accounting for lawful deductions for damage or unpaid rent, which this calculator does not subtract. This calculator does not attempt to estimate the tenant's true opportunity cost of having that money tied up -- doing so honestly would require an assumed alternative-investment return distinct from Required Interest Rate, which is outside this tool's scope; Interest Owed reflects only what the state-mandated rate (if any) actually requires the landlord to pay. Always confirm your state and local deposit caps, interest requirements, and permissible holding periods directly against current statute before relying on this as anything more than an illustrative estimate.