sq km to sq mi Converter
Turn square kilometers into square miles for countries and regions
Square kilometers to square miles FAQ
How do you convert square kilometers to square miles exactly?
The calculator uses the standard relationship where 1 square kilometer ≈ 0.3861021585 square miles. That comes from the exact definition of one mile as 1609.344 meters, which means one square mile is 2.589988110336 square kilometers. To convert from sq km to sq mi, you divide by 2.589988110336 or, more simply, multiply by 0.3861021585. For example, 100 sq km becomes about 38.61 sq mi. The tool applies this precise factor and handles the rounding so you can copy results straight into maps, notes or reports.
Why do some maps or websites show slightly different sq mi values?
Many maps, textbooks and websites use rounded factors like 0.39 or 0.386 instead of 0.3861021585. Over small regions the difference is tiny, but for large territories it can shift the result by a fraction of a square mile or more. This converter keeps the full precision of the square kilometer to square mile factor and only rounds the display, so reusing the same areas later always gives consistent numbers.
What’s 1000 square kilometers in square miles?
Using the precise factor, 1000 sq km ≈ 386.10 sq mi. Many people round this to 386 sq mi in articles or fact sheets. Similarly, 50 sq km is about 19.31 sq mi, 250 sq km is about 96.53 sq mi, and 10,000 sq km is roughly 3861 sq mi. The converter produces these results automatically so you do not need to rebuild any formulas.
Is a square kilometer bigger or smaller than a square mile?
A square mile is larger than a square kilometer. Because one square kilometer is only about 0.3861 sq mi, the square mile numbers will always look smaller for the same physical area. This converter keeps the actual land size constant and simply expresses it in whichever unit your audience or data source prefers to use.
Can I use this for countries, states and national parks?
Yes. The sq km to sq mi converter is ideal for geography, environmental science, policy briefs and news stories. You might receive official figures in square kilometers but want to compare them with square-mile statistics in an atlas or factbook. Type the sq km value from your source and paste the sq mi result into tables, GIS labels, presentations or classroom worksheets.
Is there a quick mental shortcut for sq km to sq mi?
A handy rule of thumb is to multiply by 0.4 and then subtract about 3 %. For example, 200 sq km → 200 × 0.4 = 80, minus a little gives roughly 77 sq mi, close to the exact 77.22 sq mi. Another rough check is to divide by 2.6; for many everyday sizes this lands you near the precise answer. The calculator always uses the exact 0.3861021585 factor, so your mental shortcuts are just for sanity checks.
From metric land areas to familiar square-mile sizes
This sq km to sq mi converter is built for moments when your data is in square kilometers but your audience thinks in square miles. That is common when you use international datasets alongside U.S. or U.K. sources, compare national parks from different countries, or talk about climate, population or conservation across regions. Instead of juggling different formulas, you type the square kilometers, tap convert, and get a clean line such as “2,500 sq km = 965.26 sq mi”.
1. Simple single-box interface for large and small regions
The layout stays minimal: a single field for square kilometers and a result card underneath. It works the same way whether you are converting a small lake, a district, a protected habitat or a whole province. Decimals are supported, so values like 12.5 sq km for a local reserve or 1234.75 sq km for a mixed-use region convert accurately. Behind the scenes, the tool applies the exact factor based on the defined mile and kilometer and formats the output for easy reading, copying and sharing.
When you need the reverse calculation, the “Swap Units” button takes you straight to the dedicated sq mi to sq km tool. You can bounce between both directions without hunting for a different page or configuring a more complex multi-unit widget.
2. Exact relationship: 1 sq km ≈ 0.3861021585 sq mi
The converter is grounded in internationally agreed definitions. One mile is defined as exactly 1609.344 meters, so one square mile is 2,589,988.110336 square meters, which equals 2.589988110336 square kilometers. Taking the inverse gives 1 square kilometer ≈ 0.3861021585 square miles. These are the same factors used in cartography, surveying and official statistics. Using them in your conversions keeps your numbers aligned with professional references and avoids small discrepancies between sources.
If you later need to move between other units such as hectares, acres or square meters, you can step up to the full area conversion calculator. It keeps the same clean style of outputs while handling more unit pairs in one place.
3. Common sq km to sq mi values at a glance
Here are some quick examples that match what the calculator produces. They help you build intuition for how large different square-kilometer figures feel in square miles:
| Square kilometers (sq km) | Square miles (sq mi) |
|---|---|
| 1 sq km | 0.39 sq mi |
| 5 sq km | 1.93 sq mi |
| 10 sq km | 3.86 sq mi |
| 20 sq km | 7.72 sq mi |
| 50 sq km | 19.31 sq mi |
| 100 sq km | 38.61 sq mi |
| 250 sq km | 96.53 sq mi |
| 500 sq km | 193.05 sq mi |
| 1000 sq km | 386.10 sq mi |
A simple mental check is to divide by about 3 and then add a little. For example, 900 sq km ÷ 3 ≈ 300; adding some extra puts you near the exact 347.49 sq mi. The converter hides all of the detailed arithmetic and just gives you the precise value based on the official factor whenever you need it.
4. Where the sq km to sq mi converter shines
You will often reach for this tool when you:
- Compare countries and regions — turn metric area figures from international datasets into square miles for audiences used to imperial units.
- Work with environmental and conservation data — match habitat extents, park sizes and watershed areas to square-mile statistics in reports and factbooks.
- Prepare maps, atlases and teaching materials — convert square-kilometer areas into square miles so all examples use the same unit system.
- Write articles and policy briefs — translate official sq km statistics into sq mi for readers more familiar with imperial measurements.
- Align mixed-unit datasets — standardise square-kilometer values into square miles before loading them into GIS tools, dashboards or analytical pipelines.
Because the underlying conversion is fixed by international definitions, this square kilometers to square miles converter returns the same answer every time for a given input. It becomes a dependable reference point as you move between raw data, maps, models and narrative explanations that mix metric and imperial area measurements.
References and further reading on sq km and sq mi
These references explain how square kilometers and square miles are defined and used:
- Square kilometre — describes the square kilometer as a metric unit for land areas such as towns, regions and countries.
- Square mile — covers the square mile as an imperial and U.S. customary unit of area and its metric equivalents.
- SI Units — Area (NIST) — provides background on square meters, square kilometers and other SI area units used in education and industry.
For official statistics, legal documents or regulated reporting, always follow your jurisdiction’s measurement standards and rounding rules when converting between sq km and sq mi.