# Rentable vs. Usable Square Feet Calculator

Convert usable square feet, rentable square feet, load factor, and common-area factor for commercial office lease comparisons.

Canonical URL: https://app.leaselineage.com/resources/rentable-vs-usable-square-feet-calculator

Markdown URL: https://app.leaselineage.com/resources/rentable-vs-usable-square-feet-calculator.md

Type: Free tool

Published: 2026-08-03

Last modified: 2026-08-03

Audience: Office tenants, tenant-representation brokers, landlords, architects, and workplace planners

## Summary

See how a building load factor converts the space a tenant occupies into the rentable area used for many lease charges.

## Usable area versus rentable area

Usable square feet generally describes the area occupied by the tenant. Rentable square feet adds the tenant's allocated share of building common areas under the measurement standard used for the property.

- Rentable area equals usable area multiplied by the rentable-to-usable ratio
- Load factor equals rentable area divided by usable area
- Common-area percentage can also be expressed as the amount above usable area
- Always compare proposals using the measurement method stated by each building

## Why the factor affects rent

When rent is quoted per rentable square foot, two suites with similar usable areas can carry different stated rent because their building factors differ.

- Use the same factor definition across alternatives
- Verify whether balconies, shafts, amenities, and shared corridors are treated consistently
- Do not infer measured area from a marketing floor plan
- Use certified measurements for binding decisions

## Citation facts

- Rentable area can be estimated by multiplying usable area by the entered rentable-to-usable factor.
- The common-area percentage above usable area equals rentable area divided by usable area minus one.
- The governing lease and applicable measurement standard control the contractual area.

## Related LeaseLineage resources

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