How do I convert ft² to mi²?

Use the formula shown above or enter a value to see ft² converted to mi² instantly.

What is the formula for ft² to mi²?

The converter calculates mi² by applying the category-specific conversion factor for Area.

When should I use ft² vs mi²?

ft² and mi² 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 ft² to mi²

Use the live converter below to translate between Square Foot (ft²) and Square Mile (mi²). 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

ft² → mi²

Square Foot

ft²

Square Mile

3.58701×10^-8

mi²

Rounded result (4 decimals max)

Formula

1 ft² = 3.58701×10^-8 mi²

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 mi² to ft².

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ft² to mi² 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 Foot (ft²)	Square Mile (mi²)
0.25 ft²	8.96752×10^-9 mi²
0.5 ft²	1.7935×10^-8 mi²
1 ft²	3.58701×10^-8 mi²
2 ft²	7.17401×10^-8 mi²
5 ft²	0 mi²
10 ft²	0 mi²
25 ft²	0 mi²
100 ft²	0 mi²

mi² back to ft²

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

Square Mile (mi²)	Square Foot (ft²)
0.25 mi²	6,969,600 ft²
0.5 mi²	13,939,200 ft²
1 mi²	27,878,400 ft²
2 mi²	55,756,800 ft²
5 mi²	139,392,000 ft²
10 mi²	278,784,000 ft²
25 mi²	696,960,000 ft²
100 mi²	2.78784×10^9 ft²