Rent Roll Income Calculator

How it is calculated

The tool applies one occupancy percentage to every unit. Monthly = N × R × (O / 100), Annual = Monthly × 12 and Potential = N × R × 12. N is the number of units, R is the average rent per unit per month and O is occupancy in percent, the share of units that actually pay rent. The potential figure is the annual rent at 100% occupancy, so the gap between it and the annual income is the rent lost to vacancy. All three inputs are required. Units must be a whole number (12.5 gives no result), occupancy must be between 0 and 100, and rent cannot be negative. Amounts display in US dollars. Because only an average rent is used, units with very different rents are better entered as separate runs.

Common mistakes

• Entering occupancy as a fraction (0.92). The field is a percentage, so 0.92 means under 1% occupied and gives $104.88 a month instead of $10,488.00.
• Treating the result as net income. Taxes, repairs, insurance, management fees and mortgage payments are not subtracted.
• Entering the annual rent per unit. The field is monthly, and the tool multiplies by 12 itself, so annual figures end up twelve times too high.
• Using the listed asking rent instead of the rent tenants actually pay. Discounts, concessions and unpaid rent make the real average lower.
• Counting a half unit or using a decimal unit count. Units must be whole numbers, and the tool shows no result for 12.5; occupancy above 100 is also refused.