Area converter
Square Feet to Acres
Square Feet and Acres measure the same quantity in different unit systems. The relationship is 1 ft² = 2.2957e-05 ac, which gives 2.2957e-05 ac per ft². Below you can convert any value, check a worked example and read the full chart.
Formula 1 ft² = 2.2957e-05 ac
Need the other direction? Acres to Square Feet.
How to convert Square Feet to Acres
A square foot is 0.09290304 square metres and is standard in US and UK property. An international acre is 4,046.8564224 square metres, historically the area a team could plough in a day.
To convert Square Feet to Acres, multiply the value in ft² by 2.2957e-05. For example, 10 ft² × 2.2957e-05 = 2.2957e-04 ac. This works because the ratio between the two units is constant for every value in area.
Worked examples
| ft² | ac |
|---|---|
| 1 ft² | 2.2957e-05 ac |
| 2.5 ft² | 5.7392e-05 ac |
| 5 ft² | 1.1478e-04 ac |
| 10 ft² | 2.2957e-04 ac |
| 25 ft² | 5.7392e-04 ac |
| 50 ft² | 0.00114784 ac |
| 100 ft² | 0.00229568 ac |
Reverse conversion
| ac | ft² |
|---|---|
| 1 ac | 43,560 ft² |
| 5 ac | 217,800 ft² |
| 10 ac | 435,600 ft² |
| 25 ac | 1,089,000 ft² |
| 50 ac | 2,178,000 ft² |
| 100 ac | 4,356,000 ft² |
When this conversion is useful
This is the calculation you need when you are comparing property listings, land size or building materials across measurement systems. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 ft² is 0.02295684 ac.
Is the conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
ft² to ac conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Square Feet (ft²) | Acres (ac) |
|---|---|
| 1 ft² | 2.2957e-05 ac |
| 2 ft² | 4.5914e-05 ac |
| 3 ft² | 6.8871e-05 ac |
| 4 ft² | 9.1827e-05 ac |
| 5 ft² | 1.1478e-04 ac |
| 6 ft² | 1.3774e-04 ac |
| 7 ft² | 1.6070e-04 ac |
| 8 ft² | 1.8365e-04 ac |
| 9 ft² | 2.0661e-04 ac |
| 10 ft² | 2.2957e-04 ac |
| 11 ft² | 2.5253e-04 ac |
| 12 ft² | 2.7548e-04 ac |
| 13 ft² | 2.9844e-04 ac |
| 14 ft² | 3.2140e-04 ac |
| 15 ft² | 3.4435e-04 ac |
| 16 ft² | 3.6731e-04 ac |
| 17 ft² | 3.9027e-04 ac |
| 18 ft² | 4.1322e-04 ac |
| 19 ft² | 4.3618e-04 ac |
| 20 ft² | 4.5914e-04 ac |
| 21 ft² | 4.8209e-04 ac |
| 22 ft² | 5.0505e-04 ac |
| 23 ft² | 5.2801e-04 ac |
| 24 ft² | 5.5096e-04 ac |
| 25 ft² | 5.7392e-04 ac |
| 26 ft² | 5.9688e-04 ac |
| 27 ft² | 6.1983e-04 ac |
| 28 ft² | 6.4279e-04 ac |
| 29 ft² | 6.6575e-04 ac |
| 30 ft² | 6.8871e-04 ac |
| 31 ft² | 7.1166e-04 ac |
| 32 ft² | 7.3462e-04 ac |
| 33 ft² | 7.5758e-04 ac |
| 34 ft² | 7.8053e-04 ac |
| 35 ft² | 8.0349e-04 ac |
| 36 ft² | 8.2645e-04 ac |
| 37 ft² | 8.4940e-04 ac |
| 38 ft² | 8.7236e-04 ac |
| 39 ft² | 8.9532e-04 ac |
| 40 ft² | 9.1827e-04 ac |
| 41 ft² | 9.4123e-04 ac |
| 42 ft² | 9.6419e-04 ac |
| 43 ft² | 9.8714e-04 ac |
| 44 ft² | 0.0010101 ac |
| 45 ft² | 0.00103306 ac |
| 46 ft² | 0.00105601 ac |
| 47 ft² | 0.00107897 ac |
| 48 ft² | 0.00110193 ac |
| 49 ft² | 0.00112489 ac |
| 50 ft² | 0.00114784 ac |
| 60 ft² | 0.00137741 ac |
| 70 ft² | 0.00160698 ac |
| 80 ft² | 0.00183655 ac |
| 90 ft² | 0.00206612 ac |
| 100 ft² | 0.00229568 ac |
Frequently asked questions
How many Acres are in 1 Square Feet?
1 ft² equals 2.2957e-05 ac.
How do I convert Square Feet to Acres?
Multiply the ft² value by 2.2957e-05. Example: 25 ft² = 5.7392e-04 ac.
What is 2.5 ft² in ac?
2.5 ft² = 5.7392e-05 ac.
Is the ft² to ac conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.