Conversion

Square Miles to Acres Converter

1 square mile = 640 ac. Enter any value to convert square miles (mi²) to acres (ac), or use the table below for common values.

Results

1 mi² =640 acsquare miles → acres

1 mi²640 ac

1 ac0.0015625 mi²

Formula: ac = mi² × 640

1 mi² in other units

1 mi² in other units
Unit	Value
square meters (m²)	2,589,988.11
square kilometers (km²)	2.58998811
square inches (in²)	4,014,489,600
square feet (ft²)	27,878,400
square yards (yd²)	3,097,600
acres (ac)	640
hectares (ha)	258.998811

Formula

ac = mi² × 640

Example: 10 mi² = 6,400 ac. To convert the other way, use mi² = ac × 0.0015625.

Square Miles to Acres conversion table

Square Miles (mi²)	Acres (ac)
1 mi²	640 ac
2 mi²	1,280 ac
3 mi²	1,920 ac
4 mi²	2,560 ac
5 mi²	3,200 ac
6 mi²	3,840 ac
7 mi²	4,480 ac
8 mi²	5,120 ac
9 mi²	5,760 ac
10 mi²	6,400 ac
15 mi²	9,600 ac
20 mi²	12,800 ac
25 mi²	16,000 ac
30 mi²	19,200 ac
40 mi²	25,600 ac
50 mi²	32,000 ac
75 mi²	48,000 ac
100 mi²	64,000 ac
250 mi²	160,000 ac
500 mi²	320,000 ac
1,000 mi²	640,000 ac

About square miles and acres

The square mile is 640 acres, used for large land areas such as counties and national parks in the US.

The acre is 43,560 square feet (about 4,047 m²), the traditional unit for farmland and building plots in the US and UK.

Other Area conversions

Acres → Square MilesReverse conversion Square Meters → Acresm² → ac Square Kilometers → Acreskm² → ac Square Inches → Acresin² → ac Square Feet → Acresft² → ac Square Yards → Acresyd² → ac Square Miles → Square Metersmi² → m² Square Miles → Square Kilometersmi² → km² Square Miles → Square Inchesmi² → in² Square Miles → Square Feetmi² → ft² Square Miles → Square Yardsmi² → yd² Square Miles → Hectaresmi² → ha Hectares → Acresha → ac

Frequently asked questions

How do I convert square miles to acres?

Use the formula ac = mi² × 640. For example, 10 mi² = 6,400 ac.

What is 1 square mile in acres?

1 mi² = 640 ac.

How do I convert acres back to square miles?

Use mi² = ac × 0.0015625. 1 ac = 0.0015625 mi².