Prorated Rent by Number of Days (1 to 31 Days)

Why 15 Days of Rent is Not Always Exactly 50% of Monthly Rent

Many tenants and property owners assume that half a month of occupancy (15 days) automatically equals exactly 50% of the monthly contract rent. However, under the mathematically standard Actual Calendar Days convention, the true percentage depends entirely on the month in question:

As demonstrated above, in a 31-day month like July, 15 days represents only 48.39% of the month. Conversely, in February, 15 days constitutes more than half the month (53.57%). Unless the lease agreement explicitly mandates the Banker's 30-Day Rule, applying a flat 50% calculation in July or February introduces an arithmetic error.

Common Day-Specific Rental Scenarios:

• 1 Day of Rent (Daily / Holdover Rate): Useful for unauthorized holdover stays, emergency accommodation extensions, or single-day lease overlaps.
• 5 Days of Rent: Typical for move-ins occurring on the 26th or 27th of a 30/31-day month.
• 7 Days of Rent (One Full Week): Equals exactly 22.58% of a 31-day month or 23.33% of a 30-day month.
• 10 Days of Rent: Typical for move-ins on the 21st or move-outs on the 10th.
• 15 Days of Rent (Half Month): The most queried proration duration in US residential leasing.
• 20 Days of Rent: Typical for mid-month move-ins occurring on the 10th or 11th.