Prorated rent calculator
Calculate a partial month's rent for a move-in, move-out, or custom date range — with every day shown in plain language.
How it works
Prorated rent = monthly amount × days charged ÷ days in the period. Amounts are held in cents so the prorated and uncharged parts always add back exactly to the monthly amount.
Actual-days divides by the real length of the month (28–31). The 30-day method always divides by 30 and treats day 31 as day 30 — both dates are inclusive.
Move-in charges from your date through the last day of the period; move-out charges from the first day through your date; a custom range charges your selected nights.
Worked example: A $3,100 rent for a move-in on March 11, charged through March 31, uses 21 of 31 actual days. 3,100 × 21 ÷ 31 = $2,100.00 prorated, with $1,000.00 uncharged.
FAQ
- Which method should I use?
- Many leases use actual days in the month, but some specify a flat 30-day (banker's) month. Use whichever your lease names; the result shows both the days and the convention so you can match it.
- Are the move-in and move-out days both charged?
- Yes. Both the start and end dates are counted as occupied nights, so a move-in on the 11th through the 31st is 21 days, not 20.
- Does this decide whether I owe prorated rent?
- No. RoomRatio only does the day-count math. Whether proration applies, and who must pay, is set by your lease and local rules.
- Can I prorate across two months?
- Not in this calculator — it works on a single rental month. Run it once per month if a move spans a month boundary.