Lot Size Calculator — acres, square feet and metres
A lot's area from frontage and depth in square feet, acres, square metres and hectares with exact factors, and any acreage drawn as a square.
A lot’s area from its frontage and depth, in square feet, acres, square metres and hectares with the exact factors — and the other way, what an acre looks like as a square.
| Square feet | — |
|---|---|
| Acres | — |
| Square metres | — |
| Hectares | — |
| Square yards | — |
| The acres above, as a square | — |
An acre is 43,560 square feet, and nobody can picture that. It is a square 208.71 feet on a side, or a 66 × 660 foot strip — a chain by a furlong, which is where the number comes from. A 100 × 150 foot city lot is 0.344 acre; a quarter-acre lot is 10,890 square feet, about 100 × 109. The last row draws any acreage as a square so a listing’s number turns into a shape.
Frontage times depth is the rectangle, and most lots are not. A flag lot, a pie-shaped corner or a lot with a rear jog is two rectangles, so the page takes a second piece. Beyond that, the survey is the answer: it carries the metes and bounds, and area from a deed’s bearings and distances is a calculation this page does not attempt. What it does do is convert the survey’s figure exactly.
The factors are definitions. 1 ft² = 0.09290304 m², 1 acre = 43,560 ft² = 4,046.8564224 m², 1 hectare = 10,000 m² = 2.4711 acres. Rounded conversions drift by a parking space on a large parcel; these do not.
Area = frontage × depth (+ the second piece). 1 acre = 43,560 ft² (66 × 660 ft); 1 ft² = 0.09290304 m² (exact); 1 ha = 10,000 m²; a square acre is √43,560 = 208.71 ft on a side.
Worked example
A lot with 100 ft of frontage and 150 ft of depth: how many acres?
- 100 × 150 = 15,000 ft².
- ÷ 43,560 = 0.344 acre; × 0.09290304 = 1,393.55 m² (0.139 ha).
- For scale, one acre is a square 208.71 ft on a side.
A third of an acre. A 40 × 60 ft rear piece brings it to 17,400 ft², 0.399 acre — two rectangles is as far as arithmetic goes; after that it is the survey.
11 values on this page were driven in a browser and compared with independently derived figures on 2026-09-05 (474 values across 56 calculators site-wide).
Questions
How many square feet in an acre?
43,560 — a square about 208.7 ft on a side, or 66 × 660 ft. A quarter acre is 10,890 ft².
How do I calculate lot size in acres?
Frontage × depth in feet, ÷ 43,560. A 100 × 150 ft lot is 0.344 acre; an irregular lot is the survey's figure, which this page converts exactly.