How do I convert mi² to mm²?

Use the formula shown above or enter a value to see mi² converted to mm² instantly.

What is the formula for mi² to mm²?

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

When should I use mi² vs mm²?

mi² 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 mi² to mm²

Use the live converter below to translate between Square Mile (mi²) 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

mi² → mm²

Square Mile

mi²

Square Millimeter

2.58999×10^12

mm²

Rounded result (4 decimals max)

Formula

1 mi² = 2.58999×10^12 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 mi².

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mi² 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.

Square Mile (mi²)	Square Millimeter (mm²)
0.25 mi²	6.47497×10^11 mm²
0.5 mi²	1.29499×10^12 mm²
1 mi²	2.58999×10^12 mm²
2 mi²	5.17998×10^12 mm²
5 mi²	1.29499×10^13 mm²
10 mi²	2.58999×10^13 mm²
25 mi²	6.47497×10^13 mm²
100 mi²	2.58999×10^14 mm²

mm² back to mi²

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

Square Millimeter (mm²)	Square Mile (mi²)
0.25 mm²	9.65255×10^-14 mi²
0.5 mm²	1.93051×10^-13 mi²
1 mm²	3.86102×10^-13 mi²
2 mm²	7.72204×10^-13 mi²
5 mm²	1.93051×10^-12 mi²
10 mm²	3.86102×10^-12 mi²
25 mm²	9.65255×10^-12 mi²
100 mm²	3.86102×10^-11 mi²