How to calculate prorated rent for a mid-month move-in
A tenant moves in on the 20th instead of the 1st. Nobody wants to charge a full month, and nobody wants to argue about pennies either. Prorating gets you to the right number, but there are three common ways to do it, and they give slightly different answers.
The three common methods
All three start the same way: find a daily rate, then multiply by the number of days the tenant is in the unit, counting the move-in day. They differ only in the daily rate.
- Actual days in the month: monthly rent ÷ days in that month.
- 30-day month: monthly rent ÷ 30, every month.
- Annual: monthly rent × 12 ÷ 365.
Worked example: $1,500 rent, move-in October 20
October has 31 days. A tenant moving in on the 20th occupies the 20th through the 31st, which is 12 days.
| Method | Daily rate | 12 days |
|---|---|---|
| Actual days (31) | $48.39 | $580.65 |
| Annual (365) | $49.32 | $591.78 |
| 30-day month | $50.00 | $600.00 |
The gap is about $19 here. In a 30-day month like September, the actual-days and 30-day methods give the same answer. In February the actual-days method charges more per day: a February 15 move-in, 14 days in a 28-day month, comes to $750.00.
Picking a method
The actual-days method is the most precise. The 30-day method is the easiest to explain. The annual method treats every day of the year the same. Any of them is reasonable. What matters is that the lease names one, so the tenant can check the math. Our prorated rent calculator runs all three.
Move-outs
Prorating at move-out is less automatic. If a month-to-month tenant gives notice that ends mid-month, the rent owed depends on the lease and your state's notice rules, and many states require notice that lines up with the rental period. See month-to-month notice by state.
Write it down
Put the move-in date, the prorated amount, and the method in the lease, and say when the first full month's rent is due. If the first partial month is short, some landlords collect the prorated amount together with the first full month. See what a lease must include and late fees and grace periods.