How do I convert mi² to acre?

Use the formula shown above or enter a value to see mi² converted to acre instantly.

What is the formula for mi² to acre?

The converter calculates acre by applying the category-specific conversion factor for Area.

When should I use mi² vs acre?

mi² and acre are both part of the Area category; pick the unit that matches your measurement context (e.g., scale, region, or industry standard).

Area Converter & Surface Reference

Convert mi² to acre

Use the live converter below to translate between Square Mile (mi²) and Acre (acre). Scroll further for quick examples, formula tips, and related units.

Formula insight: Most unit conversions use a simple multiplication or division by a conversion factor. The calculator shows the exact formula used.

Convert

mi² → acre

Square Mile

mi²

Acre

640

acre

Rounded result (4 decimals max)

Formula

1 mi² = 640 acre

Conversion sourcesTap or click to view references

The International System of Units (SI) — NIST Special Publication 330
National Institute of Standards and Technology (NIST). The SI Brochure (SP 330) is the definitive English edition of the BIPM SI tables. NIST’s edition lists the official constants and conversion factors tying inch-pound units to SI, which SwapUnits applies for length, mass, temperature, pressure, volume, and related conversions. See /standards/nist-si-tenfold for the complete decimal multiple/submultiple table. View source · View SI table

Results update as you type. Swap the direction to convert back from acre to mi².

Back to main converter

mi² to acre quick table

Multiply any row by the same factor to scale results. Use the converter above to enter exact values with your own units.

Square Mile (mi²)	Acre (acre)
0.25 mi²	160 acre
0.5 mi²	320 acre
1 mi²	640 acre
2 mi²	1,280 acre
5 mi²	3,200 acre
10 mi²	6,400 acre
25 mi²	16,000 acre
100 mi²	64,000 acre

acre back to mi²

Keep the reciprocal handy when double-checking calculations or undoing a conversion.

Acre (acre)	Square Mile (mi²)
0.25 acre	0.0004 mi²
0.5 acre	0.0008 mi²
1 acre	0.0016 mi²
2 acre	0.0031 mi²
5 acre	0.0078 mi²
10 acre	0.0156 mi²
25 acre	0.0391 mi²
100 acre	0.1563 mi²

Explore more area converter & surface reference

mi² → mm²

Convert into Square Millimeter without leaving SwapUnits.

mi² → cm²

Convert into Square Centimeter without leaving SwapUnits.

mi² → in²

Convert into Square Inch without leaving SwapUnits.

mi² → ft²

Convert into Square Foot without leaving SwapUnits.

mi² → yd²

Convert into Square Yard without leaving SwapUnits.

mi² → m²

Convert into Square Meter without leaving SwapUnits.

Compare all area converter & surface reference

View the full unit roster, charts, and tips for Area Converter & Surface Reference conversions.

Open category guide