Lot Size to Acres Calculator
Created by: James Porter
Last updated:
To convert a lot size to acres, multiply the length by the width in feet and divide by 43,560. A 100 × 100 ft lot is 0.23 acres and a 100 × 200 ft lot is 0.46 acres. If the plat lists four different side lengths, use the four-sides option, and if the listing gives square feet, just divide by 43,560.
Lot Size to Acres Calculator
Enter the lot's length and width, all four sides, or its area in square feet.
Lot dimensions to acres chart
Acres = length × width ÷ 43,560, for lot dimensions in feet.
| Lot (ft) | Square feet | Acres |
|---|---|---|
| 25 × 100 | 2,500 | 0.057 |
| 40 × 100 | 4,000 | 0.092 |
| 50 × 100 | 5,000 | 0.115 |
| 50 × 120 | 6,000 | 0.138 |
| 50 × 150 | 7,500 | 0.172 |
| 60 × 100 | 6,000 | 0.138 |
| 60 × 120 | 7,200 | 0.165 |
| 70 × 100 | 7,000 | 0.161 |
| 75 × 100 | 7,500 | 0.172 |
| 75 × 150 | 11,250 | 0.258 |
| 80 × 100 | 8,000 | 0.184 |
| 80 × 125 | 10,000 | 0.230 |
| 100 × 100 | 10,000 | 0.230 |
| 100 × 120 | 12,000 | 0.275 |
| 100 × 150 | 15,000 | 0.344 |
| 100 × 200 | 20,000 | 0.459 |
| 125 × 200 | 25,000 | 0.574 |
| 150 × 150 | 22,500 | 0.517 |
| 150 × 200 | 30,000 | 0.689 |
| 200 × 200 | 40,000 | 0.918 |
| 208.71 × 208.71 | 43,560 | 1.000 |
| 200 × 300 | 60,000 | 1.38 |
| 300 × 300 | 90,000 | 2.07 |
| 330 × 660 | 217,800 | 5.00 |
| 660 × 660 | 435,600 | 10.00 |
Lot size in square feet to acres, and lots per acre
| Lot size | Acres | Lots per acre |
|---|---|---|
| 2,500 sq ft | 0.057 | 17.4 |
| 5,000 sq ft | 0.115 | 8.7 |
| 6,000 sq ft | 0.138 | 7.3 |
| 7,500 sq ft | 0.172 | 5.8 |
| 8,712 sq ft | 0.200 | 5.0 |
| 10,000 sq ft | 0.230 | 4.4 |
| 10,890 sq ft | 0.250 | 4.0 |
| 15,000 sq ft | 0.344 | 2.9 |
| 21,780 sq ft | 0.500 | 2.0 |
How to calculate lot acreage
Rectangular lots
Multiply the frontage by the depth and divide by 43,560. A 75 × 150 ft lot is 11,250 sq ft, or 0.258 acres.
Lots with four unequal sides
Plats often list four side lengths, such as 101 × 127 × 105 × 134. If the corners are close to square, average the opposite sides and multiply the averages. The calculator's four-sides mode does this. It is a good estimate for typical subdivision lots, but it overstates the area of lots with sharply angled corners.
Triangular and odd-shaped lots
Split the lot into rectangles and triangles, find each area (a triangle is base × height ÷ 2) and add them up. For a legal or sale figure, rely on the recorded survey, plat or county assessor record.
Frequently Asked Questions
How do I convert lot size to acres?
Multiply the lot’s length by its width to get square feet, then divide by 43,560. A 100 × 150 ft lot is 15,000 sq ft, which is 15,000 ÷ 43,560 = 0.344 acres. If a listing gives the lot size in square feet already, just divide by 43,560.
How many acres is a 100 × 100 lot?
A 100 × 100 ft lot is 10,000 sq ft, or 0.230 acres, a little under a quarter acre (10,890 sq ft).
How do I find the acreage of a lot with four different side lengths?
For a lot that is close to rectangular, average each pair of opposite sides and multiply the two averages. A lot of 101, 127, 105 and 134 ft (going around) is about ((101 + 105) ÷ 2) × ((127 + 134) ÷ 2) = 103 × 130.5 = 13,442 sq ft, or 0.31 acres. This slightly overstates the area when the corners are far from square, so use the survey or plat for an exact figure.
How many lots are in an acre?
Divide 43,560 by the lot size in square feet. An acre holds about eight 5,000 sq ft lots, five 8,712 sq ft lots (one fifth of an acre each) or four quarter-acre lots, before allowing for streets and setbacks, which typically take 20 to 30% of a subdivision.
Is a 7,500 sq ft lot a quarter acre?
No. A quarter acre is 10,890 sq ft. A 7,500 sq ft lot is 0.172 acres, roughly one sixth of an acre.
How many acres is 132 by 323 feet?
132 × 323 = 42,636 sq ft, which is 0.979 acres, just under one acre.
Does lot size include the house?
Yes. Lot size is the area of the whole parcel, including the footprint of the house, driveway and yard. It is different from the home’s square footage, which measures the living space inside.
Sources and References
- NIST: U.S. Survey Foot. Since January 1, 2023, the acre is defined as 43,560 international square feet.