LOT SIZE
Lot size calculator
Enter frontage and depth to get lot area in square feet and in acres. It is the fastest way to size lots off a site plan while the subdivision is still being laid out.
THE MATH
How it's calculated
Area = frontage × depth. Acres = area ÷ 43,560. Multiply by the lot count for a block total.
WORKED EXAMPLE
Given: 70 ft of frontage by 120 ft of depth
Result: 70 × 120 = 8,400 sq ft, and 8,400 ÷ 43,560 = 0.193 acres
QUESTIONS
Lot size calculator questions
Does this work on an irregular lot?
As an estimate only. Frontage × depth assumes four right angles. For a pie-shaped cul-de-sac lot, a wedge or a lot with a curved rear line, use the area printed on the recorded plat.
Which measurement is the frontage?
The width at the front property line, measured along the street. Depth runs from the front line to the rear line. A corner lot fronts two streets, and the zoning code decides which one counts.
How do I estimate a cul-de-sac lot?
Average the front width and the rear width, then multiply by the depth. That is the trapezoid area, and it is close enough for planning. It is not close enough for a listing.
Is buildable area the same as lot area?
No. Subtract the front, side and rear setbacks and any easement to get the buildable envelope. A 9,100 sq ft lot can easily have well under half of that available to build on.
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