Free tool
Prorated rent calculator
Move-in or move-out mid-month? Enter the rent and the date and get the prorated amount, by actual days in the month or the 30-day method, with the arithmetic shown so you can put it in the lease.
Educational calculator, not legal advice. A few jurisdictions regulate proration method or rounding; your lease language controls. Nothing you type here is stored.
How prorated rent is calculated
One formula, two conventions:
Prorated rent = (monthly rent ÷ days in the month) × days occupied.
The only disagreement is the denominator. The actual-days method divides by the real length of that month (28 to 31 days), so the daily rate changes month to month. The 30-day "banker's month" always divides by 30, which is simpler but slightly overcharges tenants in 31-day months and undercharges in February. Most leases and most landlords use actual days; whichever you pick, write it into the lease so nobody argues at move-out.
Worked example
Rent is $2,400 and the tenant moves in on June 20. June has 30 days, and the tenant occupies June 20 through 30, which is 11 days:
$2,400 ÷ 30 = $80.00 per day → $80.00 × 11 days = $880.00
Same rent, but a July 20 move-in (31-day month): $2,400 ÷ 31 = $77.42 per day × 12 days = $929.03 by actual days, versus $880.00 by the 30-day method. That $49 gap is the whole methods debate.
When the prorated month is usually paid
Standard practice protects the landlord: collect a full first month's rent plus the deposit at signing, then apply the prorated amount to the second month. A tenant who moves in on the 20th pays the full month upfront and a small second-month bill, instead of starting the tenancy on a $880 payment. It also keeps the rent due date on the 1st from day one.
Move-out proration
Same math from the other end: the tenant pays for the days through the move-out date. A tenant leaving June 11 owes 11 days. Where move-out proration gets messy is when notice periods and lease end dates disagree; the lease's holdover and notice clauses control, and the deposit is not a substitute for the last month's prorated rent unless the lease says so. Track what was actually owed and received per tenancy in a rent ledger, and the move-out reconciliation writes itself.