Acre to Square Mile Converter

Area Converter

20 units available

Decimals:

From

To

0.001563

1 ac = 0.001563 mi²

Formula:

mi² = ac × 0.0015625

With your value: 1 ac = 0.0015625 mi²

How big is that?

Everyday references on a logarithmic scale, all expressed in acre so you can sanity-check the result.

Parking space (1/3.2e+2 your value)0.00309 ac

Tennis court (1/16 your value)0.0645 ac

Your value1.00 ac

Football pitch (1.8× your value)1.76 ac

Hectare (2.5× your value)2.47 ac

Central Park (8.4e+2× your value)843 ac

Other Acre to Square Mile conversions

2 ac to mi² 3 ac to mi² 4 ac to mi² 5 ac to mi² 6 ac to mi² 7 ac to mi² 8 ac to mi²

Acre to Square Mile Conversion Table

Acre (ac)	Square Mile (mi²)
0.5	0.000781
1	0.001563
2	0.003125
5	0.007813
10	0.015625
15	0.023438
20	0.03125
25	0.039063
50	0.078125
100	0.15625
250	0.390625
500	0.78125
1000	1.5625

Square Mile to Acre Conversion Table

Square Mile (mi²)	Acre (ac)
0.5	320
1	640
2	1,280
5	3,200
10	6,400
15	9,600
20	12,800
25	16,000
50	32,000
100	64,000
250	160,000
500	320,000
1000	640,000

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Acre (ac)

Area

Exact conversion

Derived from the square metre via the length definitions above.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Square Mile (mi²)

Area

Exact conversion

Derived from the square metre via the length definitions above.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Acre to Square Mile

To convert from Acre (ac) to Square Mile (mi²), multiply the value by 0.0015625.

Formula: mi² = ac × 0.0015625

Reverse: ac = mi² × 640

Step-by-Step Example

Start with your value in Acre. For example: 5 ac
Multiply by the conversion factor: 5 x 0.0015625
The result is: 0.007813 mi²

About Acre

The acre is a unit of land area equal to 43,560 square feet or about 4,047 square meters. It is used primarily in the US, UK, and former British colonies.

Fun Fact: An acre was originally defined as the amount of land a yoke of oxen could plow in one day.

Common uses: land measurement, agriculture, real estate.

About Square Mile

The square mile equals 640 acres or about 2.59 square kilometres, and is the standard unit for US county, city and land-survey areas.

Common uses: census areas, land surveys, geography.

Frequently Asked Questions

How many Square Mile are in 1 Acre?

There are exactly 0.0015625 Square Mile in 1 Acre. This means the conversion factor from Acre to Square Mile is 0.0015625.

What is the formula to convert Acre to Square Mile?

The formula to convert Acre to Square Mile is: mi² = ac × 0.0015625. For example, to convert 10 Acre to Square Mile, you would multiply 10 by 0.0015625.

What is a Acre?