Security Deposit

Calculating a Security Deposit and Its Move-Out Refund

A security deposit is an upfront payment held by a landlord to cover unpaid rent or damage beyond normal wear and tear, refunded (in full or in part) after a tenant moves out. Enter your monthly rent and a multiplier — how many months’ rent the deposit equals — and this calculator finds the deposit amount. Add move-out deductions to see the refund you should expect back.

The Formula

• Security deposit = Monthly Rent × Deposit Multiplier.
• Refund due = Security Deposit − Deductions.
• Deductions % = Deductions ÷ Security Deposit × 100.

Worked Example

$1,500 monthly rent with a 1.5x deposit multiplier:

1. Security deposit: $2,250 ($1,500 × 1.5).
2. With $300 in move-out deductions, the refund due is $1,950 ($2,250 − $300), or 13.3% withheld.

Key Factors to Consider

• Most states legally require a landlord to return a deposit (or an itemized list of deductions) within a specific time window after move-out. This window commonly ranges from 14 to 30 days depending on the state — a landlord holding a deposit well past that legal deadline without explanation may be violating local tenant-protection law.
• Move-in and move-out documentation is one of the most practical things a tenant can do to protect a deposit refund. Photos or a written condition report at move-in, kept and compared against the unit’s condition at move-out, gives concrete evidence if a deduction is later disputed — this is widely recommended precisely because “he said, she said” disputes over pre-existing damage are common.
• Some jurisdictions require a landlord to pay interest on a held security deposit. A few states and cities mandate that deposits be held in a separate account and accrue interest paid to the tenant, either annually or at move-out — worth checking local law, since this varies significantly and isn’t universal.
• A security deposit and “last month’s rent” are sometimes treated as legally distinct, even when collected together. Some jurisdictions have different rules for how each can be used and refunded — a lease combining the two should be read carefully to understand which protections apply to which portion of the upfront payment.

Common Mistakes

• Assuming every state or city allows the same deposit size. Security deposit limits — where they exist — are set state by state (and sometimes city by city) and can change through legislation. This calculator only does the math; check your local landlord-tenant laws for any cap that applies where you live.
• Confusing normal wear and tear with damage. Faded paint or carpet worn down from ordinary use generally can’t be deducted from a deposit, while damage a tenant caused (holes in walls, broken fixtures) generally can — the exact line depends on local law.
• Not budgeting for the deposit alongside first month’s rent. A 1.5x or 2x deposit on top of the first month’s rent can add up to a large upfront cost — check how it fits into your overall Budget Calculator before signing a lease.

Useful to Know

• Want to protect against damage costs that could eat into your deposit? Renters Insurance Cost Calculator covers your own belongings and liability, which is a separate but related concern.
• Planning your overall move-in costs, not just the deposit itself? Budget Calculator helps you see how the deposit fits alongside first month’s rent and other upfront expenses.