Square Miles (mi²) to Square Kilometers (km²) Converter
Enter a value to instantly convert between area units.
1 Square Mile = 2.59 Square Kilometer
Key Formulas
Acre → Square Foot
ft² = ac × 43560Square Foot → Acre
ac = ft² × 0.0000229568Hectare → Acre
ac = ha × 2.47105Acre → Hectare
ha = ac × 0.404686Formula
km² = mi² × 2.589988110336One square mile equals 2.59 km² — this is a fixed relationship (1 mi = 1.609 km exactly). US geographers frequently convert mi² to km² for international publications, environmental reports, and cross-border planning. It's one of the most common area conversions in geography.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A cartographer noting 1 mi² = 2.59 km² for map legend international editions.
1 mi² = 2.59 km²
A regional planner converting 10 mi² city area to km² for European sister-city agreement documentation.
10 mi² = 25.9 km²
An environmental scientist calculating 100 mi² national park to km² for UNESCO World Heritage nomination.
100 mi² = 259 km²
A demographer converting 500 mi² metropolitan area to km² for international population density comparison.
500 mi² = 1295 km²