Price Per Unit

Price per unit (or "per door") is the purchase price divided by the number of units. A 50-unit apartment building bought for $5,000,000 is $100,000 per unit.

How it's used: it's the headline comp metric for multifamily. Brokers and buyers quote per-unit pricing to benchmark a deal against recent sales in the submarket and against what it would cost to build the same units new (replacement cost).

Why it matters: per-unit price is a basis sanity check that the cap rate alone won't give you. A deal can show an attractive cap rate yet sit well above replacement cost or comps — a sign the in-place NOI is being pushed. Conversely, buying meaningfully below replacement cost is a durable margin of safety. Always read per-unit price next to the per-unit rent and the cap rate together.

Formula: Price per unit = Purchase price ÷ Number of units

For non-residential assets, the equivalent is price per square foot. Model the income side on the multifamily pro-forma calculator and see the multifamily underwriting guide.