Parking Requirement Calculator (Spaces by Use)
Calculate the minimum parking spaces a zoning code requires from floor area, dwellings, rooms or seats for each use — office, retail, restaurant, medical, warehouse, residential, hotel, assembly, school — for up to three mixed uses with a shared-parking (time-of-day) credit, reductions, rounding, accessible (ADA), EV and bicycle spaces, a check of the spaces you provide, and the land and cost the parking takes.
How it works
Spaces per use = floor area ÷ 1,000 × ratio (or ÷ 100 m²), or units / rooms / seats × ratio · Mixed use = sum of the uses, or with shared parking the highest period total of Σ(spaces × occupancy %) · × (1 − reduction), rounded (up by default) · Accessible per ADA Table 208.2, 1 in 6 van-accessible · EV and bicycle = share × spaces · Land = spaces × 325–400 ft² (≈ 30–37 m²) per space ÷ levels
Zoning codes traditionally require a minimum number of off-street spaces per unit of floor area or per dwelling, using ratios drawn from peak-demand surveys of suburban sites — about one space per 300 ft² of office, one per 250 of retail and ten per 1,000 ft² of restaurant. Multiply through and the parking often outgrows the building: with aisles a surface space consumes about 325 ft², so a 40,000 ft² office needs a lot nearly as large as its own floor plate. For a mixed-use site, add a second and third use under More options: the code minimum is normally the sum, but many codes let uses with different peaks share spaces. The shared-parking option applies a widely used occupancy table — office full on weekday days but 5–20% at night, residential and hotel full overnight, restaurants full in the evening, churches on weekend days — and sizes for the busiest of six periods. The accessible-space count follows the 2010 ADA Standards table, EV-ready and bicycle requirements are being added, and transit or demand-management reductions trim the total. Because structured spaces cost tens of thousands of dollars each, parking minimums shape what gets built; many cities have now reduced or abolished them.
Worked example
A 40,000 ft² office at 1 space per 300 ft² needs 40 × 3.33 = 133.2, rounded up to 134 spaces — 5 of them accessible (1 van) — covering about 43,550 ft² of surface lot, a full acre and slightly more than the building itself, at roughly $804,000. A 20% transit reduction would cut it to 107 spaces. Add a 10,000 ft² restaurant (100 spaces) and the sum is 234; with shared parking the busiest period is weekday daytime, when the office is full and the restaurant at 70%, so 133.2 + 70 = 204 spaces are enough — 30 fewer.
Sources: ADA.gov — Restriping parking spaces (2010 ADA Standards, table 208.2) · City of Madison, AL — Shared parking ordinance (occupancy rates by period)
Frequently asked questions
Gross or net floor area?
Most codes use gross floor area; some use net leasable or exclude storage and mechanical. Restaurants are sometimes rated per seat (1 per 3–4 seats) instead of per square foot.
How does shared parking work?
Each use’s minimum is multiplied by the share of it occupied in each period — weekday and weekend, daytime, evening and night — and the site is sized for the busiest period instead of the sum. Office peaks on weekday days, restaurants and theatres in the evening, residential and hotels overnight, churches on weekend days. The ULI/ITE method does the same hour by hour; credits of 20–40% are typical when peaks differ.
How many accessible spaces do I need?
Under the 2010 ADA Standards (table 208.2): 1 for up to 25 spaces, 2 for 26–50, 3 for 51–75, 4 for 76–100, then one more per 50 up to 200 and per 100 up to 500, 2% for 501–1,000, and 20 plus 1 per 100 over 1,000. One in six must be van-accessible. The count is based on the total spaces you provide.
Should fractional spaces be rounded up?
Most codes round any fraction up; some round to the nearest whole space (0.5 up) or drop fractions below a threshold. Pick the rule your code uses under More options.
Can I enter the floor area in square metres?
Yes. Choose m² and enter the area; the default ratios convert to spaces per 100 m², and any override ratio you type is read per 100 m² too.
Related calculators
Planning arithmetic using the definitions most zoning codes share; the actual FAR, setbacks, height, coverage, parking ratios and density rules are set by the local ordinance and overlay districts, and many cities exclude or bonus certain areas. Confirm with the zoning code and a land-use professional before relying on a yield.