Acre (ac)
An acre is 43,560 square feet, or exactly 4,046.8564224 square meters — a traditional land measure.
Acres parcel farmland, suburban lots, and parks in the United States, UK, and several Commonwealth countries.
Acre to Square Mile
Convert acre to square mile instantly. Type in either field — results update live.
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Area Acre Square Mile
1 acre = 0.0015625 square miles
Unit
Unit
Conversion table
Selected ac values converted to mi² using the exact factor from this tool.
| ac | mi² |
|---|---|
| 0.01 | 0.000015625 |
| 0.1 | 0.00015625 |
| 1 | 0.0015625 |
| 2 | 0.003125 |
| 3 | 0.0046875 |
| 5 | 0.0078125 |
| 10 | 0.015625 |
| 20 | 0.03125 |
| 50 | 0.078125 |
| 100 | 0.15625 |
| 1,000 | 1.5625 |
How to convert
Exact conversion factors in both directions, plus a worked example.
1 ac = 0.0015625 mi²
1 mi² = 640 ac
To convert acre to square mile, multiply by 0.0015625.
To convert square mile to acre, multiply by 640.
Example: convert 10 ac to mi²
10 × 0.0015625 = 0.015625 mi²
About these units
Short background on the units used in this conversion.
Square Mile (mi²)
A square mile is the area of a square one mile per side, equal to 640 acres or about 2.59 square kilometers.
Square miles describe city limits, national parks, and geographic regions in the US and UK.
Frequently asked questions
How many square miles are in one acre?
One acre equals 0.0015625 square miles. Multiply your acres value by 0.0015625 to convert to square miles.
What is the conversion formula?
mi² = ac × 0.0015625The reverse is
ac = mi² × 640, using the same exact factors as this converter.Is this Acre to Square Mile converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.
All acre conversions
Jump to any area conversion starting from acre — including the reverse direction and every other unit in our dataset.
square mile (mi²) → acre (ac)
acre (ac) → square meter (m²)acre (ac) → square kilometer (km²)acre (ac) → square centimeter (cm²)acre (ac) → square millimeter (mm²)acre (ac) → square micrometer (µm²)acre (ac) → square nanometer (nm²)acre (ac) → square decimeter (dm²)acre (ac) → square dekameter (dam²)acre (ac) → square hectometer (hm²)acre (ac) → hectare (ha)acre (ac) → are (a)acre (ac) → barn (b)acre (ac) → square mile (us survey) (mi² surv)acre (ac) → sectionacre (ac) → square yard (yd²)acre (ac) → square foot (ft²)acre (ac) → square foot (us survey) (ft² surv)acre (ac) → sabinacre (ac) → square inch (in²)acre (ac) → circular inch (circ in)acre (ac) → acre (us survey) (ac surv)acre (ac) → square rod (rd²)acre (ac) → square rod (us survey) (rd² surv)acre (ac) → square perch (perch²)acre (ac) → square pole (pole²)acre (ac) → square chain (ch²)acre (ac) → roodacre (ac) → township (twp)acre (ac) → homesteadacre (ac) → square mil (mil²)acre (ac) → circular mil (circ mil)acre (ac) → square nautical mile (NM²)acre (ac) → arpentacre (ac) → cuerdaacre (ac) → plazaacre (ac) → varas castellanas cuad (varas cast.)acre (ac) → varas conuqueras cuad (varas con.)acre (ac) → electron cross section (σₑ)