Square Kilometers to Square Miles Converter

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Convert square kilometers to square miles using the squared linear factor: 1 mile = 1.609344 km, so 1 mi² ≈ 2.59 km² and 1 km² ≈ 0.3861 mi². Reference: Paris ≈ 105 km² ≈ 40.5 mi²; London ≈ 1,572 km² ≈ 607 mi²; Texas ≈ 695,662 km² ≈ 268,597 mi². Useful for translating European-style city/region areas into US-style mi². Browser-local.

Square kilometer (km²)
Square mile (mi²)

Square kilometer (km²) → Square mile (mi²)

Quick reference table

Square kilometer (km²)Square mile (mi²)
1 km²0.3861 mi²
2 km²0.7722 mi²
5 km²1.9305 mi²
10 km²3.861 mi²
25 km²9.6526 mi²
50 km²19.3051 mi²
100 km²38.6102 mi²

Glossary

Square kilometer (km²)

A square kilometer equals 1,000,000 m² or 100 hectares. It is the standard unit for city, region and country areas on metric maps. 1 km² ≈ 0.3861 mi² ≈ 247.1 acres. Note: 1 km² = 1,000,000 m² (not 1,000), because area scales as the square of length. The city of Paris covers about 105 km².

Square mile (mi²)

A square mile equals 640 acres or about 2.59 km² (since 1 mi = 1.609 km, 1 mi² = 1.609² km² = 2.59 km²). Used for US/UK city and county areas. The city of Chicago covers about 234 mi²; the state of Texas is about 268,597 mi². 1 km² ≈ 0.3861 mi².

Metric / SI area

In the metric system, area is reported in square meters (SI base) and its scaled units — square millimeter, square centimeter, square kilometer — plus the convenient hectare (10,000 m²) for land. Each step is exactly 100× the previous because area scales as the square of length: 1 m² = 100 dm² = 10,000 cm² = 1,000,000 mm². This squared scaling is the most common manual-conversion error.

Imperial / US Customary area

US customary and UK imperial systems use square inch, square foot, square yard, acre and square mile (144 in² = 1 ft², 9 ft² = 1 yd², 4,840 yd² = 1 acre, 640 acres = 1 mi²). The acre — historically the area a team of oxen could plow in a day — survives as the standard land-parcel unit in the US. Linked to metric by 1 ft² = 0.09290304 m² exactly.

Related tools

Square Miles to Square Kilometers
Convert mi² to km² — 1 mi² ≈ 2.59 km²
Square Meters to Square Kilometers
Convert m² to km² — 1,000,000 m² = 1 km² (not 1,000!)
Hectares to Acres
Convert hectares to acres — 1 ha ≈ 2.471 acres
Area Converter
Convert area — mm², cm², m², ha, km², in², ft², yd², acres, mi²