What is the km² to mi² Converter?

This tool converts square kilometers to square miles, helping present geographic data in terms familiar to American audiences.

When This Conversion Matters

Square kilometers are the global standard for measuring large areas, but Americans typically think in square miles. This conversion is useful for:

Comparing countries — how does France compare to Texas?
Understanding news — wildfire areas, flood zones, protected regions
Educational content — presenting world geography to US students
Travel planning — understanding destination sizes

The Conversion

1 square kilometer = 0.3861 square miles

Alternatively, 1 square mile ≈ 2.59 square kilometers. Germany (357,000 km²) is about 138,000 mi² — roughly the size of Montana.

Scale Reference

For perspective: the United States covers 9.83 million km² (3.80 million mi²), making it the third-largest country by area. Converting international geographic data helps contextualize this scale.

How to Use

Enter square kilometers — type the geographic area
See square miles — the US-friendly result appears instantly
Copy for reference — use in articles, reports, or presentations

Country Size Comparisons

How various countries compare in US terms:

Japan (378,000 km²) = 146,000 mi² — about the size of California
United Kingdom (243,000 km²) = 94,000 mi² — smaller than Michigan
France (643,000 km²) = 248,000 mi² — slightly smaller than Texas
Germany (357,000 km²) = 138,000 mi² — similar to Montana
Australia (7.69M km²) = 2.97M mi² — slightly smaller than the contiguous US

Making Data Relatable

When you read that a rainforest lost 10,000 km², this equals 3,861 mi² — roughly the size of Puerto Rico. These comparisons make international data meaningful.

Reverse Conversion

Click the swap button (↔) to convert square miles to square kilometers.

Converter Features

Instant Real-Time Conversion

See square mile equivalents as you type. Compare international geographic data to familiar US references instantly.

Bidirectional Conversion

Switch between km² and mi² with one click. Work in whichever direction your data requires.

One-Click Copy

Copy converted values for articles, presentations, or educational materials targeting American audiences.

Geographic Scale Reference

Country and region sizes for perspective:

100 km² (38.6 mi²) - Small city area
1,000 km² (386 mi²) - Large metropolitan region
10,000 km² (3,861 mi²) - Small country or US state
100,000 km² (38,610 mi²) - Medium-sized country

Mobile-Optimized Design

Convert geographic data on your phone when reading international news or preparing presentations.

Frequently Asked Questions

What is the conversion factor for km² to mi²?

1 km² = 0.3861 mi². Conversely, 1 mi² = 2.59 km². One square mile is larger than one square kilometer.

Why do most countries use square kilometers?

The kilometer is the metric standard for distance, making km² the natural unit for area. Only the US, UK (partially), and a few other countries commonly use square miles.

How can I quickly estimate km² to mi²?

Divide by 2.5 for a rough estimate. For 1,000 km²: 1,000 ÷ 2.5 = 400 mi². The exact answer is 386 mi²—reasonably close.

How big is Germany compared to US states?

Germany (357,000 km² = 138,000 mi²) is slightly smaller than Montana (147,000 mi²) and larger than New Mexico (121,000 mi²).

What's a good comparison for understanding km²?

Central Park (3.4 km²) = 1.3 mi². Manhattan (59 km²) = 23 mi². Rhode Island (4,001 km²) = 1,545 mi². Use familiar places for perspective.

Is this conversion used in science?

Scientific papers use metric (km²), but when communicating to American audiences, converting to mi² improves understanding without sacrificing accuracy.

Square Kilometers to Square Miles