Security Deposit Calculator
Check if a security deposit amount is legal and calculate allowable interest earned.
Security deposit rules vary dramatically by province and state: Ontario permits only a last month's rent deposit (no damage deposit), BC caps deposits at half a month's rent, and Alberta allows one month. Enter your jurisdiction and monthly rent to calculate the maximum legal deposit, required interest, and return deadline — with a link to the official government source.
Select your region for jurisdiction-specific rules (deposit caps, rent increase limits, transfer taxes, and more).
Inputs
Results
Maximum Legal Deposit
$2,000
Deposit Status
✓ Within limit
Interest Owed (if required)
$50
Understanding This Calculator
Learn how deposit caps and interest rules differ by province and state, and how to check whether a requested deposit is legal.
How the math works
Two calculations run in parallel. First, the legality check: Maximum legal deposit = Monthly rent × your jurisdiction's cap. Ontario allows only a last month's rent deposit of one month (no damage deposits); BC caps security deposits at half a month's rent; Alberta allows one month; many US states allow one to two months or set no cap.
Second, interest: where required, Interest owed = Deposit × annual rate × years held. Ontario's rate equals the annual rent-increase guideline; most US states require no interest at all. The calculator applies the rule pack for your selected jurisdiction.
Worked example
Using the defaults in Ontario: rent of $2,000, a requested deposit of $2,000, held for 1 year.
- Maximum legal deposit = one month's rent = $2,000 → the request is legal
- Interest at the 2.5% guideline: 2,000 × 2.5% × 1 = $50 owed to the tenant
The same $2,000 request in BC would be flagged: the cap there is half a month's rent, or $1,000 (plus a separate half-month pet deposit if applicable).
How to read the result
If the requested deposit exceeds the legal maximum, the excess is generally not collectible, and a tenant who already paid it can usually recover the overage through the provincial or state tribunal. If interest is owed, it accrues to the tenant — in Ontario it is often applied by topping up the last month's rent deposit to the current rent level.
Deposit type matters as much as amount: Ontario landlords cannot take a damage deposit at all, only last month's rent and a refundable key deposit. When in doubt, check the official tenancy authority for your jurisdiction or get legal advice.