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Let's convert Acres (ac) to Square Miles (mi²)

This quick and easy calculator will convert Acres (ac) to Square Miles (mi²) and show formula, brief history on the units and quick maths for the conversion.

Enter Acres to convert to Square Miles

Result

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Swap Units (mi² → ac)

ac in Ares (a)

ac in Barns (b)

ac in Circular Mils (cmil)

ac in Hectares (ha)

ac in Roods (ro)

ac in Square Centimetres (cm²)

ac in Square Feet (ft²)

ac in Square Inches (in²)

ac in Square Kilometres (km²)

ac in Square Metres (m²)

ac in Square Yards (ya²)

Quick Reference for Converting Acres to Square Miles

Formula

mi² = ac / 640

Quick Rough Maths

To get the Square Miles, divide the number of Acres by 640.0

Acres (ac) in 1 Square Mile

There are 640 Acres in 1 Square Mile

Square Miles (mi²) in 1 Acre

There are 0 Square Miles in 1 Acre

Unit Information

Acre
/ˈeɪkə/

Symbol: ac
Unit System: Imperial / US Customary

What is the Acre?

The acre is a unit of area and is used in the imperial and US customary systems with the symbol a.

It represents the area the size of one chain by one furlong (66 by 660 feet). This is exactly equal to 10 square chains, 1⁄640 of a square mile or 43,560 square feet.

It is generally used to measure the size of land.

Square Mile
/skwɛːˌmʌɪl/

Symbol: mi²
Unit System: Imperial

What is the Square Mile?

The square mile is a unit of area and is an imperial unit with the symbol mi².

One square mile is equal in area to a square with edges one mile in length.

The Romans established the square mile; computed through a system of feet, paces and marches. The square mile's existence still remains in some places; for example "The Square Mile" is a term often used to describe the very centre of London in the UK (which just so happens to measure 1mi²).