Free tool
Prorated rent calculator
Rent for a partial month, on whichever basis your lease uses — and what the other two would give, since the difference is what tenants query.
Enter the full monthly rent and the dates the tenant has the property.
Which basis should the lease use?
Actual days in the month is the fairest and the one a court is most likely to expect: the tenant pays for the days they had, divided by the days that month contained. Its only drawback is that the daily rate moves between February and March.
A flat 30-day monthis simpler and common in leases, but it overcharges in every 31-day month and undercharges in February — by about 7% in a leap year. If your lease uses it, say so explicitly, because a tenant who recalculates on actual days will find a different number.
365 ÷ 12 gives a stable daily rate all year and is the lowest of the three for a short stay. It is defensible and rarely disputed, but it needs to be in writing because nobody assumes it.
Count both ends
A tenant who moves in on the 20th and stays through the 30th has the property for 11 days, not 10. This tool counts inclusively. The two commonest proration disputes are this off-by-one and the choice of denominator, and both are avoidable in one sentence of the lease.
Common questions
- Which proration basis is correct?
- All three are used. Actual days in the month is the fairest and the one a court is most likely to expect. A flat 30-day month is simpler but overcharges in 31-day months and undercharges in February. 365 divided by 12 gives a stable daily rate. What matters is that the lease names one.
- Do I count both the first and last day?
- Yes. A tenant occupying the 20th through the 30th has the property for 11 days, not 10. This off-by-one is the second commonest proration dispute after the choice of denominator.
- How much difference does the basis make?
- Enough to argue about. On $1,800 rent for 10 days of February, the three bases give $642.86, $600.00 and $591.78. The calculator shows all three so you can see the spread.
- Is prorated rent required by law?
- Generally it is a matter of contract rather than statute, so the lease governs. Some states require proration in specific situations such as early termination by a service member.
Have the software do this every time
Pacific Rentals Pro applies these rules to every lease and every move-out automatically, using the same verified state data as this page.
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