Is proration always calculated by day?

Usually, but some contracts prorate by month or even by hour — check your specific agreement for which unit of time it uses.

Can I use this for a partial refund?

Yes — enter the full amount you paid, the full period it covers, and the number of days remaining unused to estimate a prorated refund.

Pro Rata Calculator

Calculate a prorated amount for a partial period — rent for a partial month, a partial subscription refund, or salary for a partial pay period.

Full amount

Full period

days

Actual days used

days

Prorated Amount

$1,500.00

How It Works

The proration formula

Prorated amount = (full amount ÷ full period length) × actual days used. This spreads the full amount evenly across the period and charges only for the portion actually used.

Example

Moving into an apartment halfway through a 30-day month with $3,000 rent means paying for 15 days: $1,500.

Common Mistakes

Using calendar months without adjusting for months with different lengths (28-31 days) — always use the actual number of days in that specific period.
Forgetting that some landlords or providers prorate using a fixed 30-day month regardless of the actual month length — confirm which method applies to your situation.

Frequently Asked Questions

Is proration always calculated by day?: Usually, but some contracts prorate by month or even by hour — check your specific agreement for which unit of time it uses.
Can I use this for a partial refund?: Yes — enter the full amount you paid, the full period it covers, and the number of days remaining unused to estimate a prorated refund.