About the Price per Unit (Door) Calculator
Price per unit — usually called price per door — divides the purchase price of an apartment building by its number of rental units. It is the quickest way to compare multifamily properties of different sizes: a 16-unit building at $2.4 million and a 48-unit building at $6.5 million cost $150,000 and about $135,400 per door respectively. Brokers, appraisers and lenders quote price per door alongside cap rate when discussing multifamily sales.
Enter the price, number of units, total bedrooms and rentable square feet, plus the gross annual rent and net operating income if you have them. The calculator returns price per door, per bedroom and per square foot, the gross rent multiplier, the cap rate and average rent per unit. Enter a comparable price per door from recent sales to estimate what the building would be worth on that basis.
Use it to screen listings and sanity-check offers, but remember that price per door ignores unit mix, condition and rents. Pair it with the cap rate and rent per unit so a building full of studios is not mistaken for a bargain against one full of three-bedroom units.
With the default inputs, the price per door is $150,000.00. Change any value above to recalculate instantly.
How to use the price per unit (door) calculator
- 1Enter the purchase or asking price.
- 2Enter the number of units, total bedrooms and rentable square feet.
- 3Add gross annual rent and NOI for GRM and cap rate.
- 4Optionally enter a comparable price per door from recent sales.
- 5Compare price per door alongside cap rate and rent per unit before making an offer.
Formula and method
Each size-based metric divides the purchase price by a different measure of the building: rental units (doors), bedrooms, or rentable square feet. Price per door is the multifamily standard; price per bedroom and per square foot help when comparing buildings with different unit mixes or unit sizes.
The gross rent multiplier divides price by gross annual rent and the cap rate divides net operating income by price, tying the size metrics back to income. Multiplying a comparable price per door by the number of units gives a quick sales-comparison estimate of value, which should be adjusted for location, condition, amenities and rent levels.
- Doors
- Number of rentable units
- GRM
- Gross rent multiplier
- NOI
- Net operating income
Worked examples
16-unit building for $2.4M
$2,400,000 ÷ 16 units = $150,000 per door, $85,714 per bedroom and $166.67 per square foot. Gross rent of $230,400 ($1,200 per unit per month) gives a 10.42× GRM, and $138,000 of NOI is a 5.75% cap rate. Comparable sales at $160,000 per door imply a $2.56M value.
48-unit complex for $6.5M
The larger building costs about $135,417 per door but $90,278 per bedroom — more per bedroom than the 16-unit example because it has fewer bedrooms per unit. At $125,000 per door comps imply $6.0M, so the asking price is about $500,000 above comparable sales despite a 6% cap rate.
Frequently asked questions
What is price per door in real estate?+
Price per door is the purchase price of a multifamily property divided by its number of rental units. A $3 million building with 20 apartments costs $150,000 per door. It is used to compare apartment buildings of different sizes.
What is a good price per door?+
It depends entirely on the market, property class, unit size and rents. A good price per door is one at or below recent comparable sales for similar buildings in the same area, supported by a cap rate that meets your return target.
Is price per door or price per square foot better?+
Neither alone is enough. Price per door is the multifamily convention, but it treats a studio and a three-bedroom unit the same. Price per square foot and per bedroom adjust for unit size and mix, and income metrics like cap rate check value against rent.
How do I value an apartment building using price per unit?+
Find recent sales of similar buildings nearby, calculate each sale’s price per door, and multiply the typical figure by your building’s unit count. Then adjust for condition, location, amenities and rent levels, and cross-check with an income approach.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.