Prorated Rent Calculator

PARTIAL-MONTH RENT TOOL

Prorated Rent Calculator

Calculate rent for an inclusive date range within one calendar month. Compare actual calendar days, a fixed 30-day convention and a 365-day annual basis. Currency changes formatting only; it does not convert values.

Both dates count. They must fall in the same calendar month. A complete month returns the regular monthly rent for every method.

How prorated rent is calculated

Prorated rent is the portion of a monthly rent assigned to fewer than all the days in a rental month. The calculator counts both the first and last charged dates. Because leases and local rules can use different conventions, it shows three common methods instead of assuming one universal answer.

  • Actual calendar days: prorated rent = monthly rent ÷ days in that calendar month × charged days.
  • Fixed 30-day month: prorated rent = monthly rent ÷ 30 × charged days.
  • 365-day annual basis: prorated rent = monthly rent × 12 ÷ 365 × charged days.

If the selected range covers every date in the month, the calculator returns one full monthly rent for all three methods. This prevents a complete 31-day month from being billed above the agreed monthly amount under a 30-day convention.

Checked examples

Actual-days example: For US$2,000 monthly rent from January 15 through January 31, there are 17 charged days in a 31-day month. The calculation is US$2,000 ÷ 31 × 17 = US$1,096.77.

30-day example: The same 17 days using a fixed 30-day month are US$2,000 ÷ 30 × 17 = US$1,133.33.

365-day example: The daily rate is US$2,000 × 12 ÷ 365 = US$65.7534. For 17 days, the prorated rent is US$1,117.81.

Leap-year check: February 10 through February 29, 2028 contains 20 charged days. Using actual calendar days, US$2,000 ÷ 29 × 20 = US$1,379.31.

Which method should you use?

Use the method stated in the lease, property policy or applicable local rule. Actual calendar days changes the daily rate between 28-, 29-, 30- and 31-day months. A fixed 30-day method keeps the divisor constant. A 365-day basis first converts twelve months of rent into an annual daily rate. The calculator compares the methods so tenants and landlords can see the monetary difference before agreeing on a charge.

Important limits

  • The two dates must be valid, inclusive and within the same calendar month.
  • The calculation covers rent only. It does not automatically prorate utilities, parking, storage, concessions, deposits, late fees, taxes or other charges.
  • Currency selection changes the symbol and number format only; no exchange-rate conversion occurs.
  • This is an arithmetic tool, not legal advice. It does not decide which convention a lease or jurisdiction requires.
  • Monthly rent must be greater than zero and cannot exceed one billion currency units.

Related calculators

Check whether the full monthly amount fits your budget with the Rent Affordability Calculator, model a change in rent with the Rent Increase Calculator, or allocate a shared lease with the Rent Split Calculator.