Real Estate & Investing
Unit Mix / Rent Roll Calculator
Enter the unit count and rents for each unit type to total current rent, market rent, and the upside between them.
Calculation inputs
Leave a unit type at zero units if the property does not include it.
Results
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Complete the fields and select Calculate to show results here.
About this calculator
This calculator totals current and market rent across a property's unit mix — studios, one-bedrooms, two-bedrooms, and three-bedrooms — to show the income upside if every unit were leased at market rent. Investors use it to gauge how much a rent roll could grow over time.
How the calculation works
- Total current gross rent = sum of (units × current rent) for each unit type
- Total market gross rent = sum of (units × market rent) for each unit type
- Rent upside = market gross rent − current gross rent
- Rent upside % = rent upside ÷ current gross rent × 100
Notes and assumptions
Lease expirations determine how quickly upside can actually be captured.
Market rents should be supported by recent comparable leases, not asking prices.
How it works in plain English
For each unit type you enter the number of units, the current monthly rent, and the market monthly rent. The calculator multiplies units by rent for each type and sums across all types to get total current monthly rent and total market monthly rent, so you can see the full rent roll at a glance rather than adding up unit types by hand.
Subtracting current rent from market rent produces the monthly rent upside in dollars, along with that upside expressed as a percentage of current rent. The calculator also annualizes all three totals and calculates the average current rent per unit across the whole property, which is a common shorthand figure used when comparing properties of different sizes.
A breakdown table shows the current rent, market rent, and dollar upside for each individual unit type, which makes it easy to see which unit type contributes the most to the overall upside. This is useful for prioritizing which units to renovate or reprice first as leases turn over, since focusing on the unit type with the largest gap between current and market rent typically produces the fastest return on any renovation spending.
The formula
- Total current rent = sum of (units x current rent) across unit types
- Total market rent = sum of (units x market rent) across unit types
- Rent upside = total market rent - total current rent
- Rent upside % = (rent upside / total current rent) x 100
Worked example
A property has 2 studios at $900 current and $1,050 market rent, 4 one-bedrooms at $1,150 current and $1,325 market rent, and 2 two-bedrooms at $1,400 current and $1,650 market rent. Current monthly rent totals $8,300, and market monthly rent totals $9,650.
The monthly upside is $1,350, or about 16.3% above current rent. Annualized, that's $16,200 in additional rent per year if every unit were brought up to market rent as leases expire. The breakdown table would show the one-bedrooms contributing the largest share of that upside, at $700 a month across four units, making them the logical priority for repricing as those leases come up for renewal.
Frequently asked questions
How should I estimate market rent for each unit type?
Market rent should be based on recent comparable leases signed for similar units nearby, not asking rents from active listings, which tend to run higher. Local rental listing data, appraisals, or a broker opinion of rent are common sources.
Can I capture the full rent upside immediately?
Usually not. Rent upside assumes every unit can be repositioned to market rent, but in practice this happens gradually as leases expire, and rent control or stabilization rules in some areas limit how quickly and by how much rent can increase.
What if a unit type has zero units at my property?
Leave that unit type's fields at zero. The calculator automatically excludes any unit type with zero units from the totals and from the breakdown table, so it won't affect your results or distort the average rent per unit figure calculated across the property.
Does this calculator account for the cost of renovating units to reach market rent?
No, it only compares rent levels. If reaching market rent requires renovation, factor those costs and the time units may sit vacant during turnover into a separate cash flow or return analysis, since a large rent upside can still be a poor short-term investment if the renovation and vacancy costs are high enough.
How is average rent per unit useful if unit sizes differ?
Average current rent per unit gives a single blended figure across all unit types, which is useful for quick comparisons between properties. For decisions about individual unit types, the breakdown table gives more precise, type-specific figures.
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