Area measurement

BOMA Rentable Area Calculator

Estimate rentable area using usable occupant area and an editable common-area load factor. Confirm the applicable BOMA standard and building measurements before lease use.

What this calculator estimates

Estimate rentable area from usable area and common-area allocation. It combines the inputs below to produce Estimated rentable area. Every assumption remains editable so the estimate can reflect the property, financing and location being evaluated.

Worked example

Using the displayed sample assumptions, the calculator produces 5,750 sq. ft.. This is an illustration, not a market quote. Change one input at a time to understand what drives the result.

Inputs and assumptions

• Usable occupant area — sample input: 5000 sq. ft.
• Common-area load factor — sample input: 15 %
• Other allocated rentable area — sample input: 0 sq. ft.

How to interpret the result

Confirm the measurement standard required for the assignment. Compare a conservative case with an expected case and keep a record of the assumptions used.

Common mistake to avoid

Do not combine above-grade, below-grade and rentable areas without labels. Local definitions, taxes, lending practices and measurement requirements can materially change the result.

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Reviewed 2026-09-08.