How do I convert acre to mm²?

Use the formula shown above or enter a value to see acre converted to mm² instantly.

What is the formula for acre to mm²?

The converter calculates mm² by applying the category-specific conversion factor for Area.

When should I use acre vs mm²?

acre and mm² 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 acre to mm²

Use the live converter below to translate between Acre (acre) and Square Millimeter (mm²). 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

acre → mm²

Acre

acre

Square Millimeter

4.04686×10^9

mm²

Rounded result (4 decimals max)

Formula

1 acre = 4.04686×10^9 mm²

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 mm² to acre.

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acre to mm² quick table

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

Acre (acre)	Square Millimeter (mm²)
0.25 acre	1.01171×10^9 mm²
0.5 acre	2.02343×10^9 mm²
1 acre	4.04686×10^9 mm²
2 acre	8.09371×10^9 mm²
5 acre	2.02343×10^10 mm²
10 acre	4.04686×10^10 mm²
25 acre	1.01171×10^11 mm²
100 acre	4.04686×10^11 mm²

mm² back to acre

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

Square Millimeter (mm²)	Acre (acre)
0.25 mm²	6.17763×10^-11 acre
0.5 mm²	1.23553×10^-10 acre
1 mm²	2.47105×10^-10 acre
2 mm²	4.94211×10^-10 acre
5 mm²	1.23553×10^-9 acre
10 mm²	2.47105×10^-9 acre
25 mm²	6.17763×10^-9 acre
100 mm²	2.47105×10^-8 acre