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About this tool
Convert square kilometers to square miles instantly. Free, bidirectional, and fully in-browser.
1 square kilometer equals 0.3861021585 square miles — enter any square kilometer value to convert it to square miles instantly. This Square kilometer to Square mile converter is a client-side tool: it applies a single multiplication (mi² = km² × 0.3861021585) in your browser, updates the moment you type, and works in both directions — edit either field, or press swap, to convert square miles back to square kilometers. A reference table lists common square kilometer values already converted, and nothing you enter is sent to a server.
Open Square kilometer to Square mile Converter on AltFTool — it loads instantly in your browser.
Type the value you want to convert into the Square kilometer field.
Read the equivalent in square miles in the result field, and copy it if needed.
Use the decimal-places slider for more or less precision, or press swap to convert square miles to square kilometers.
The result updates as you type, and the swap button flips the conversion to square mile → square kilometer without reloading.
The conversion uses the precise factor (mi² = km² × 0.3861021585), so the number matches a manual calculation to the decimal places you choose.
A slider sets 0–10 decimal places, and very small or very large results switch to scientific notation instead of rounding to zero.
Everything runs locally in your browser — no upload, no account, no limit on conversions.
One square kilometer is 0.3861021585 square miles. Multiply the square kilometer value by 0.3861021585 to convert. For example, 10 km² = 3.861021585 mi².
mi² = km² × 0.3861021585. This tool applies it automatically and shows a worked example: 10 km² = 3.861021585 mi².
Yes. Press the swap button, or type into the square mile field, and the tool converts square miles to square kilometers using the inverse of the same relationship.
It uses the standard area definition (mi² = km² × 0.3861021585), not a rounded approximation, so results are exact to the number of decimal places you select.
Yes. The converter is a browser-side script with no network calls: your values are never uploaded, and once the page has loaded it keeps working without a connection.
Add the Square kilometer to Square mile Converter widget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
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