Prorated Rent Calculator
Find out exactly how much rent you owe for a partial month — using both common calculation methods, side by side.
The date you get the keys and start living there.
Leave blank if you only need the first-month calculation.
How Is Prorated Rent Calculated?
There are two widely used methods. Both are accepted by most landlords — the difference is small in most months but can add up in short months like February.
30-Day (Banker's Month) Method
Pretends every month has exactly 30 days. Simple and consistent.
Example: $1,500 ÷ 30 × 16 days = $800.00
Actual-Days Method
Uses the real number of days in the calendar month.
Example in May (31 days): $1,500 ÷ 31 × 16 days = $774.19
Ready to Make It Official?
A solid lease agreement should spell out the exact prorated amount, when it's due, and which calculation method was used. Get a completed, ready-to-sign document for your state in minutes.
Create Your Lease Agreement — $7.99 →Frequently Asked Questions
Prorated rent is a partial month's rent you pay when you move in or move out in the middle of a billing period. Instead of paying a full month, you only pay for the days you actually live there. For example, if you move in on the 15th, you pay for roughly half a month rather than the full month.
Most landlords use the 30-day (banker's month) method because it's simple and gives the same result every month regardless of February's short month or July's 31 days. The actual-days method is more precise — it divides rent by the real number of days in that month. Either method is generally acceptable unless your lease or state law specifies one.
In most states, there is no law requiring a landlord to prorate rent. However, many landlords do prorate as a matter of fairness and to attract tenants. Your best protection is to have the proration amount and method written into your lease before you sign.
A few states have guidelines or common practices. California courts have generally favored the actual-days method when disputes arise. Most states leave it to the landlord's or lease's discretion. When in doubt, check your signed lease — whatever method it specifies is the one that applies to you.
Usually yes. Most landlords collect the first month's prorated rent (along with the security deposit) before or on the day you receive the keys. Your lease should spell out exactly when prorated rent is due — always read it carefully before signing.
No. Security deposits are almost always based on a full month's rent, not on your prorated amount. Proration only affects how much you pay for the partial first or last month, not the deposit amount.
If you paid a full month up front and move out before the month ends, you may be entitled to a refund for the unused days — but only if your lease allows early termination and specifies a proration refund. Always check your lease terms and give proper written notice before moving out.
The safest approach is to write the exact prorated amount, the calculation method used, and the due date directly into the lease agreement. A state-specific, completed lease agreement makes this easy — all the key fields are already included.