What is a parking ratio?

A parking ratio states how many parking spaces correspond to a defined amount of building area, such as spaces per 1,000 sq ft or per 100 m². Some land uses instead use employees, seats, rooms, bedrooms, or dwelling units, which are not interchangeable with an area-based ratio.

What floor area should I use — gross or net?

Use the exact area definition attached to the ratio you are applying. A code or lease may specify gross floor area, gross leasable area, net rentable area, or defined exclusions. Mixing the numerator from one rule with a different area definition produces a misleading result.

Does the required-space result always round up?

The calculator shows the exact mathematical result and a rounded-up whole-space planning figure. Legal rounding rules vary: a code may round up, round to the nearest whole number, disregard a fraction, or apply another rule. Verify the controlling ordinance before treating the planning figure as a requirement.

Does this tool account for ADA accessible spaces?

No — ADA minimums are determined by total space count under the ADA Standards for Accessible Design (Table 208.2), not by building area. Use the total calculated here as the input to determine how many must be accessible.

Can I use square metres?

Yes. Select the metric basis to calculate spaces per 100 m² directly. Do not convert a rate expressed per 1,000 sq ft into a per-100 m² rate by simply reusing the same number; the two area bases are different.

Parking Ratio Calculator

Calculate parking ratios and planning space counts in US or metric units, then verify the area definition and rounding rule in your local code.

Inputs

Area & ratio basis

Building Area (sq ft)

Calculation Mode

Find ratio from space count Find required spaces from ratio

Number of Parking Spaces

Result

Enter values and click Calculate.

Before Using This for Compliance

Confirm the land-use category and whether the rate is a minimum, maximum, or target.
Use the specified area definition: GFA, GLA, net rentable area, or another defined basis.
Check the jurisdiction's fractional-space rounding rule and any exemptions or reductions.
Calculate accessible spaces separately from the total facility count under the applicable accessibility standard.

Summary

Calculate parking ratios and planning space counts in US or metric units, then verify the area definition and rounding rule in your local code.

How it works

Choose square feet per 1,000 sq ft or square metres per 100 m².
Enter the building area using the area definition required by your source or local code.
Choose your calculation mode: ratio lookup or required-space estimate.
For ratio mode: enter the number of available parking spaces to get the ratio.
For spaces mode: enter a target ratio (e.g. 4 per 1,000 sq ft) to get required spaces.
Review the exact result and the rounded-up planning count, then apply the rounding rule required by your jurisdiction.

Use cases

Verify a commercial development meets local zoning parking minimums.
Compare a proposed building's parking supply to industry benchmarks.
Convert a published metric parking ratio into a space count without manual unit conversion.
Evaluate parking supply for a building conversion or change of use.
Prepare parking demand tables for a site plan application.
Check whether a shared-parking arrangement is feasible.

Frequently Asked Questions

Last updated: 2026-09-20 · Reviewed by Nham Vu