How to calculate prorated rent (with examples)

Prorated rent is the partial rent a tenant pays for part of a month, usually the first month when they move in after the 1st, or the last month when they move out before the end of it. The basic math is simple: work out a daily rate, then multiply it by the number of days the tenant has the place. The part that trips landlords up is which daily rate to use, because there are three common methods and they give slightly different answers. Here is each one, with worked examples you can check against your own numbers.

The short answer

Prorated rent = daily rate x days occupied. The most common way to get the daily rate is to divide the monthly rent by the number of days in that month. Count the move-in day as a day the tenant owes, and count through the last day of the month.

Example: rent is $1,500 and the tenant moves in on September 20. September has 30 days, so the daily rate is $1,500 / 30 = $50. The tenant has the place from the 20th through the 30th, which is 11 days. Prorated rent is $50 x 11 = $550.

The three ways to calculate a daily rate

Whichever method you choose, write it into the lease and use it every time. Consistency matters more than which method you pick.

• Days in that month. Monthly rent divided by the actual number of days in the month (28, 29, 30 or 31). This is the most common and the easiest to explain. The daily rate changes a little from month to month.
• Days in the year. Annual rent (monthly rent x 12) divided by 365. The daily rate is the same all year, which some landlords find fairer.
• 30-day month. Monthly rent divided by 30, no matter how many days the month has. Simple mental math, but it slightly overcharges in 31-day months and undercharges in February.

Worked examples

Here is the same $1,500 rent with a move-in on the 20th, calculated all three ways in three different months:

The differences are small in most months but can reach $40 or more in February. That is enough to cause a disagreement if the method is not written down, which is why the lease should say which one you use.

How to count the days

Most disputes over prorated rent are really disputes about counting. A few rules keep it clean:

• Count the move-in day. If the tenant gets the keys on the 20th, the 20th is a day they owe. From the 20th through the 30th is 11 days, not 10. A quick check: last day minus first day, plus one.
• For a move-out, count from the 1st through the last day the tenant has possession, as the lease defines it.
• Leap years: February has 29 days in a leap year, so the "days in that month" rate changes. The "days in the year" method normally still uses 365; if you prefer 366 in leap years, say so in the lease.
• Round to the cent and round the same way every time.

Move-in late in the month? Consider combining

When a tenant moves in during the last few days of a month, a separate prorated payment of $150 followed by full rent a week later is awkward for everyone. Many landlords collect the prorated amount together with the next full month at move-in. For a move-in on September 26 at $1,500, that would be 5 days at $50 ($250) plus October's $1,500, for $1,750 at move-in, and then full rent from November.

Whatever you decide, put the exact amounts and dates in the lease or a move-in letter, so there is nothing to interpret later.

Is a landlord required to prorate rent?

For a move-in, prorating is usually a business choice, not a legal requirement. You can start a lease on the 1st, start it mid-month and prorate, or start the rent cycle on the move-in date (rent due on the 20th of each month). Prorating keeps every tenant on the same due date, which makes bookkeeping and reminders simpler.

Move-outs are different. Whether rent must be prorated when a tenant leaves early, or when a lease ends mid-month, depends on the lease, your state's law and the notice the tenant gave. Some states have rules about rent after a tenant gives notice or after a landlord re-rents the unit. Check your state's rules before you charge a full month for a partial one.

Put it in the lease

A one-line clause saves the argument. For example: "Rent for any partial month is calculated by dividing the monthly rent by the number of days in that month and multiplying by the number of days of occupancy, including the move-in day." Then list the first payment amount and due date in the lease itself.

How RentMerchant fits

In RentMerchant you handle a prorated first month with a one-time invoice for the partial amount, then set up a recurring monthly rent schedule that starts on the next full month. The schedule creates and emails each month's invoice on its own, a set number of days before the due date that you choose. Tenants pay online by bank transfer or card, get a receipt, and see every charge and payment in their portal.

If a tenant pays the prorated amount in cash or by check, you record it against the invoice so the ledger stays complete. For the full record-keeping side, see our rent ledger guide, and if this is your first tenant, the first-time landlord checklist covers the rest of move-in.