This converter switches between square feet and acres in both directions — the standard tool for sizing building plots, paddocks, and land parcels measured in US/imperial units. Type into either box and the other fills in instantly.
How it works
The whole conversion rests on one exact definition: 1 acre = 43,560 square feet.
- Square feet to acres: acres = ft² ÷ 43,560
- Acres to square feet: ft² = acres × 43,560
The figure 43,560 comes from an acre’s historic definition of one chain (66 ft) by one furlong (660 ft), since 66 × 660 = 43,560.
Quick reference table
| Square Feet | Acres | Typical context |
|---|---|---|
| 5,445 ft² | 0.125 ac (⅛ acre) | Small suburban lot |
| 10,890 ft² | 0.25 ac (quarter-acre) | Common residential lot |
| 21,780 ft² | 0.5 ac (half-acre) | Generous suburban lot |
| 43,560 ft² | 1.0 ac | One full acre |
| 87,120 ft² | 2.0 ac | Small hobby farm parcel |
| 100,000 ft² | ~2.296 ac | Two-plus acres |
| 435,600 ft² | 10.0 ac | Small rural tract |
Worked examples
Lot sizing: A listing says a plot is 10,000 ft². How does that compare to an acre?
10,000 ÷ 43,560 ≈ 0.2296 acres — just under a quarter-acre.
Parcel to square feet: A land deed describes 2.5 acres and you want to fence the perimeter.
2.5 × 43,560 = 108,900 ft². To estimate fencing, note a square parcel of that area has sides of about 330 feet each (√108,900 ≈ 330 ft), for a perimeter of roughly 1,320 feet.
Agricultural use: A farmer wants to plant on three acres.
3 × 43,560 = 130,680 ft² — just over 130,000 square feet of growing area.
Practical tips
- Real estate listings in the US typically describe lots under one acre in square feet and lots over one acre in acres. This converter bridges both.
- Zoning ordinances often specify minimum lot sizes in square feet or fractional acres. Converting the given standard lets you compare parcels directly.
- Survey documents report areas in acres with decimal fractions. If the survey says 1.75 acres, multiply by 43,560 to get
76,230 ft²— a useful sanity check against the plat map. - Common mistake: Don’t confuse the area in square feet with a square that is 43,560 feet on a side (that would be enormous). An acre of any shape totals 43,560 ft².
- Running conversions on irregular parcels? Break the land into rectangles, convert each to acres, and sum the results.
The conversion runs entirely in your browser, with no uploads and no tracking.