📅 Prorated Rent Calculator

When you move in or out mid-month, you shouldn't have to pay the full month's rent — only for the days you actually occupy the unit. There are two common methods: the actual-days-in-month method divides rent by that month's real day count (28-31) then multiplies by occupied days, while the flat 30-day method always divides by 30. For example, on $900/month rent, moving in on the 16th of a 30-day month and staying through month-end gives 30−16+1=15 occupied days. Flat-30: 900/30×15 = $450. Since that month actually has 30 days too, the actual-days method also gives $450.

Now try a 31-day month (say, January) with the same day-16 move-in (16 occupied days): actual-days gives 900/31×16 ≈ $464.52, while flat-30 gives 900/30×16 = $480 — a real difference. Because the two methods diverge whenever the month isn't exactly 30 days, it's worth confirming which method your lease uses before signing.

Which method is more favorable depends on how many days are in that particular month. In a 31-day month (Jan, Mar, May, Jul, Aug, Oct, Dec), the actual-days method (÷31) produces a lower per-day rate than the flat-30 method (÷30), which favors the tenant. In February (28 or 29 days), the actual-days method (÷28) produces a higher per-day rate than flat-30, which favors the landlord. In 30-day months (Apr, Jun, Sep, Nov), both methods give identical results. The gap is usually small, but if your lease doesn't specify a method, it's worth calculating both and proposing whichever is fairer before you sign. Many property managers and commercial leases default to flat-30 for simple accounting, so always check the actual terms of your lease or your landlord's stated policy first.