Acre to Square mile Converter
Type a value — the answer appears instantly. 1 ac = 0.0015625 mi².
Reviewed by the OmniCalc teamMethod verified 2026-07-01
0.0015625 square miles
= 4,046.86 m²= 43,560 ft²
equals 0.0015625 square milesFormula: mi² = ac × 0.0015625
Acre to Square mile formula
mi² = ac × 0.0015625
Convert 5 acres to square miles
- Start with 5 acres.
- Multiply by the conversion factor: 5 × 0.0015625 = 0.0078125.
- So 5 ac = 0.0078125 mi².
Acre to Square mile conversion table
| Acres (ac) | Square miles (mi²) |
|---|---|
| 0.01 ac | 0.000015625 mi² |
| 0.1 ac | 0.00015625 mi² |
| 0.25 ac | 0.000390625 mi² |
| 0.5 ac | 0.00078125 mi² |
| 1 ac | 0.0015625 mi² |
| 2 ac | 0.003125 mi² |
| 3 ac | 0.0046875 mi² |
| 4 ac | 0.00625 mi² |
| 5 ac | 0.0078125 mi² |
| 6 ac | 0.009375 mi² |
| 7 ac | 0.0109375 mi² |
| 8 ac | 0.0125 mi² |
| 9 ac | 0.0140625 mi² |
| 10 ac | 0.015625 mi² |
| 15 ac | 0.0234375 mi² |
| 20 ac | 0.03125 mi² |
| 25 ac | 0.0390625 mi² |
| 30 ac | 0.046875 mi² |
| 40 ac | 0.0625 mi² |
| 50 ac | 0.078125 mi² |
| 75 ac | 0.1171875 mi² |
| 100 ac | 0.15625 mi² |
| 250 ac | 0.390625 mi² |
| 500 ac | 0.78125 mi² |
| 1,000 ac | 1.5625 mi² |
| 5,000 ac | 7.8125 mi² |
| 10,000 ac | 15.625 mi² |
Unit definitions
What is a acre?
The acre is exactly 4840 square yards, about 4046.86 square metres or 0.405 hectares. It is the traditional unit for land area in the United States and United Kingdom. An acre was historically the area a yoke of oxen could plough in a day.
What is a square mile?
The square mile is the area of a one-mile square, containing 640 acres or about 2.59 square kilometres. It is used for large land areas, counties, and statistical regions in the United States. One square mile is roughly 259 hectares.
Frequently asked questions
How many square miles are in one acre?
One acre equals 0.0015625 square miles (1 ac = 0.0015625 mi²).
How do I convert acres to square miles?
Multiply the value in acres by 0.0015625. For example, 10 ac × 0.0015625 = 0.015625 mi².
Which is bigger — a acre or a square mile?
A square mile is bigger: one square mile contains 640 acres.
Is this acre to square mile converter free?
Yes — the converter is free, works offline once loaded, and computes instantly in your browser without sending your numbers to a server.
Conversion factors follow international definitions (SI / NIST). Last verified 2026-07-01.