Security deposit interest calculator

Statewide and unconditional: Connecticut, Maryland (deposits ≥ $50 held 6+ months), Massachusetts (held 1+ year), Minnesota, New Jersey, and DC (12+ month tenancies). Conditional: Illinois (25+ unit landlords), New York (6+ unit buildings), Ohio (deposits over one month's rent), Pennsylvania (held 2+ years), Florida (only if held in an interest-bearing account), plus New Hampshire, New Mexico, North Dakota, and Iowa in narrower cases. Chicago requires it citywide regardless of Illinois's threshold.

It varies by state: Connecticut 0.49% (annual deposit index), Maryland 3.47% (greater of 1.5% or the 1-year Treasury rate), Massachusetts up to 5%, Minnesota 1% (fixed), Illinois 0.005% statewide / Chicago 0.01%, Ohio 5% on the portion above one month's rent. States like New Jersey and New York pay the actual bank rate rather than a published figure.

Penalties are real: Massachusetts imposes mandatory treble damages plus attorney's fees, Chicago awards double the deposit plus fees, DC allows treble damages for bad faith. This is one of the most commonly litigated small-claims issues for landlords in interest states.

Usually simple, computed annually — Maryland's statute explicitly says simple interest accrued monthly, Minnesota's is simple noncompounded 1%. A few jurisdictions require paying or crediting interest annually, which effectively compounds it if left with the deposit. Check the statute cited on your state's card above.