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Real Asphalt Calculator

Parking Lot Calculator

Enter the size of your lot and a stall angle to see how many parking spaces fit, a scaled layout, the ADA accessible spaces you need, and how much asphalt and money the paving takes.

By the Real Asphalt Calculator team · Updated · How we calculate

Your lot

ft
ft
Stall angle
in
$/sq ft
$/stall

Quick answer

With 9 × 18 ft stalls and 24 ft two-way aisles, 90° parking needs about 300 to 350 sq ft per space, so an acre fits roughly 125 to 145 cars. A 200 × 130 ft lot fits about 76 stalls, takes around 628 tons of asphalt at 4 inches, and needs 4 ADA accessible spaces.

Parking stall and aisle dimensions

The calculator uses 9 × 18 ft stalls, a common US default. A "module" is two rows of stalls facing a shared drive aisle.

AngleAisleStall width along aisleDouble-row module
90°24 ft two-way9.0 ft60.0 ft
60°18 ft one-way10.4 ft58.2 ft
45°13 ft one-way12.7 ft51.2 ft

How the stalls are counted

Rows run along the lot's length. One cross aisle is kept at the end of the rows so traffic can move between aisles. The lot depth is filled with as many double-row modules as fit, and a single row with its own aisle is added if the leftover depth allows. Angled rows lose a small triangle at each end.

Stalls = Rows × floor((Lot length − Cross aisle) ÷ Stall width along aisle)

Example: a 200 × 130 ft lot with 90° stalls fits two 60 ft modules (four rows). Each row is 176 ft long after the cross aisle, which holds 19 stalls, so the lot fits 76 stalls at about 342 sq ft each. Real layouts lose some spaces to islands, entrances and landscaping, so treat the result as a ceiling.

Accessible parking spaces

Total spacesAccessible spaces required
1–251
26–502
51–753
76–1004
101–1505
151–2006
201–3007
301–4008
401–5009
501–1,0002% of total
1,001 and over20, plus 1 per 100 over 1,000

From the 2010 ADA Standards for Accessible Design, §208.2. One in six accessible spaces must be van-accessible. Accessible spaces need adjacent access aisles, so they take more room than standard stalls.

Paving a parking lot

The calculator estimates tons of asphalt at your thickness using 145 lb/ft³, then prices the job per square foot installed plus striping per stall. A 200 × 130 ft lot at 4 inches takes about 628 tons of hot mix. To price the material alone, use the asphalt calculator; for upkeep, see the sealcoating calculator.

Frequently asked questions

How many parking spaces fit in an acre?

With efficient 90° rows, an acre (43,560 sq ft) fits roughly 125 to 145 spaces, based on about 300–350 sq ft per space including aisles. Landscaping, islands, entrances and odd shapes reduce that.

What is the standard parking space size?

A common US standard is 9 ft wide by 18 ft long, with a 24 ft two-way aisle for 90° parking. Some cities allow 8.5 ft stalls or require 10 ft; always check local zoning.

How many accessible parking spaces are required?

Under the 2010 ADA Standards, lots with 1–25 spaces need 1 accessible space, 26–50 need 2, 51–75 need 3 and 76–100 need 4, rising in steps after that. At least one in every six accessible spaces must be van-accessible.

Is angled or 90-degree parking more efficient?

90° parking usually fits the most cars and allows two-way traffic. Angled parking (60° or 45°) is easier to pull into and needs narrower one-way aisles, which can fit more cars on narrow lots.

How thick should a parking lot be?

About 3–4 inches of asphalt over a compacted aggregate base for car parking, and 6 inches or more where delivery trucks or buses drive.

How much does it cost to pave a parking lot?

New parking lot paving commonly costs $2.50 to $6 per square foot in 2026. A 200 × 130 ft lot (about 0.6 acres) at $4 per square foot is around $104,000 before striping, lighting and drainage.