Prorated Rent Calculator

The prorated rent calculator finds rent for a partial first or last month. Enter the full monthly rent, choose whether the tenant is moving in or moving out, and select the moving date. The calculator converts monthly rent into a daily rent using the actual number of days in that month, then multiplies by the number of occupied days.

This is the calculation renters and landlords need when a lease starts after the first, ends before the last day, or is extended for a few extra days. It is intentionally narrow: it prorates rent, not utilities, security deposits, pet fees, parking, damages, or concessions. That narrow scope makes the result easy to audit and easy to put in a lease addendum, move-in ledger, or closing email.

How to use this calculator

Start with the monthly rent from the lease. Choose moving in when the selected date is the first day the tenant receives access to the home. Choose moving out when the selected date is the final day the tenant occupies the property or owes rent. Then pick the moving date. The calculator reads the month and year from that date so February, leap years, 30-day months, and 31-day months are handled automatically.

The result shows the prorated rent, daily rent, occupied days, days in the month, and share of monthly rent. Use the 3x rent calculator to see whether the full rent meets an income rule, the budget calculator to plan the transition month, and the mortgage calculator if you are comparing renting with a purchase.

How the calculator matches the form

The calculator first checks that monthly rent is a nonnegative number and that the moving date is valid. It then finds the actual number of days in that moving date’s month. If moving out is selected, occupied days equal the day of the month. If moving in is selected, occupied days equal days in month minus the day of the month plus one. That plus one matters because the move-in date is counted.

Daily rent is monthly rent divided by days in the month. Prorated rent is daily rent multiplied by occupied days. The percentage displayed in the result is occupied days divided by days in the month, multiplied by 100.

Formula

Daily rent is:

$\text{daily rent} = \frac{\text{monthly rent}}{\text{days in month}}$

For a move-in:

$\text{occupied days} = \text{days in month} - \text{move-in day} + 1$

For a move-out:

$\text{occupied days} = \text{move-out day}$

The prorated rent is:

$\text{prorated rent} = \text{daily rent} \times \text{occupied days}$

The share of monthly rent is:

$\text{share of monthly rent} = \frac{\text{occupied days}}{\text{days in month}} \times 100$

Worked examples

For a move-in on July 18, 2026 with monthly rent of $2,400, July has 31 days. The calculator counts July 18 through July 31, or 14 occupied days. Daily rent is $2,400 divided by 31, which is $77.42. Prorated rent is $77.42 times 14, or $1,083.87. The share of monthly rent is 14 divided by 31, or about 45.16%.

For a move-out on June 12, 2026 with monthly rent of $2,100, June has 30 days. The calculator counts June 1 through June 12, or 12 occupied days. Daily rent is $2,100 divided by 30, or $70.00. Prorated rent is $70.00 times 12, or $840.00.

Both examples include the selected moving day. If the parties agree that the tenant returns keys at the start of the day and owes nothing for that date, the lease or written agreement should say so because that is different from this calculator’s default.

Practical guidance for renters and landlords

Put the proration in writing before money changes hands. The note should identify the monthly rent, the calendar month, the daily rate, the dates charged, and the amount due. If rent is paid through an online portal that only accepts full-month charges, ask the landlord how the credit or partial charge will appear on the ledger.

Be careful when a partial month overlaps with concessions. A free month, reduced first month, or landlord-paid moving credit can change the practical amount due even if the daily rent is correct. Also separate rent from security deposits. Many states limit how deposits are handled, and a deposit should not be confused with earned rent unless the lease and local law allow it.

For roommates, decide whether the proration applies to the entire unit or only to one person’s share. If one roommate moves in late, the landlord may still require full rent from the household while roommates settle the internal split. Use the same daily-count method for everyone so the allocation is defensible.

Common mistakes

• Counting the move-in day in one calculation but excluding it in another.
• Dividing by 30 for every month when the agreement says actual calendar days.
• Forgetting that February has 28 days in 2026.
• Prorating fees that the lease treats as fixed monthly charges.
• Relying on a verbal agreement instead of a dated written ledger.

Sources

• HUD, Rental Assistance — context for rental obligations and housing support.
• HUD, Fair Housing Act overview — federal protections relevant to rental housing practices.
• CFPB, What is a debt-to-income ratio? — income and monthly obligation context for housing budgets.

Formula references

• Claim: daily rent=monthlyRent/daysInCalendarMonth; prorated amount=daily rent×included occupancy days; inclusion convention must be explicit. Source: Principles of Finance, OpenStax, Rice University (peer-reviewed open textbook). Version: 2022 first edition, ISBN 978-1-951693-54-1. Jurisdiction: Jurisdiction-neutral finance definitions. Accessed 2026-07-09.

These sources support only the claims described above. This calculator is informational and does not replace qualified domain, legal, consumer-credit, payroll, mortgage, pensions, or retirement advice.