# Square Kilometers to Acres Converter

URL: https://speedycalculator.com/calculators/conversion/square-kilometers-to-acres/
Last updated: 2026-10-25

> Convert square kilometres (km²) to acres (acre): 1 square kilometre = 247.10538 acre, so multiply by 247.10538 or divide by 0.0040468564. Both fields are editable, so you can also type in acres and get square kilometres back.

## Inputs

- Square kilometres (km²)

## Results

- Acres

## Formula

```
1 km² = 247.10538 acre
1 acre = 0.0040468564 km²
acre = km² × 247.10538
```

## Explanation

One square kilometre is about 247.1 acres. City areas, national parks and farms are compared this way between metric and U.S. sources.

### How to use the Square Kilometers to Acres Converter

- Type the number of square kilometres into the **Square kilometres** field. Decimals such as 0.5 are fine.
- Read the answer in **Acres** – it updates as you type, with no button to press.
- To convert the other way, type into **Acres** and the square kilometres are recalculated.
- Press **Copy results** to copy both values with the page title, or **Copy link** to share this exact conversion.

This page converts only km² ⇄ acre. Need a different unit? Use the general area converter, where you can choose any “from” and “to” unit.

### How it works

Both units measure area, so they are always in the same ratio: one square kilometre equals 247.10538 acres. The calculator multiplies the number of square kilometres you type by 247.10538 to give acres, and when you type into the acres field it divides by the same factor to give square kilometres. Because the ratio never changes, doubling the square kilometres always doubles the acres. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation).

### How to convert square kilometres to acres

- Write down the value in square kilometres, for example **1 km²**.
- Multiply by the conversion factor 247.10538 (because 1 square kilometre = 247.10538 acre).
- 1 × 247.10538 = **247.10538 acre**.
- To go back from acres to square kilometres, divide by 247.10538 – or multiply by 0.0040468564.

### km² to acre conversion table

Square kilometresAcresAcresSquare kilometres0.1 km²24.710538 acre1 acre0.0040468564 km²0.5 km²123.55269 acre2 acre0.0080937128 km²1 km²247.10538 acre5 acre0.020234282 km²2 km²494.21076 acre10 acre0.040468564 km²5 km²1,235.5269 acre20 acre0.080937128 km²10 km²2,471.0538 acre50 acre0.20234282 km²100 km²24,710.538 acre100 acre0.40468564 km²1,000 km²247,105.38 acre1,000 acre4.0468564 km²

### What is a square kilometre?

A square kilometre is a million square metres, or 100 hectares. Areas of cities, countries, lakes and national parks are reported in km².

### What is an acre?

An acre is exactly 43,560 square feet, about 4,047 m². Historically it was the land a team of oxen could plough in a day. It remains the land unit in the U.S. and UK.

### Quick mental conversion

For a fast estimate, multiply square kilometres by about **250** to get acres; the error is about 1.2%. Use the calculator above when you need the exact figure.

### Common mistakes to avoid

Converting area with a length factor (1 m = 3.28 ft, but 1 m² = 10.76 ft², not 3.28 ft²), and assuming regional land units such as marla, bigha or katha have one standard size everywhere.

## Worked example

Inputs — Square kilometres: 1 km².

Results — **Acres = 247.10538147 acre**.

## FAQ

**How many acres in a km²?**
About 247.105 acres.

**How many hectares in a km²?**
100 ha.

**How do I convert square kilometres to acres?**
Multiply the number of square kilometres by 247.10538. For example, 1 km² × 247.10538 = 247.10538 acre.

**How do I convert acres back to square kilometres?**
Divide by 247.10538 (or multiply by 0.0040468564), or simply type the value into the acres field above.

**What is 10 km² in acres?**
10 km² = 2,471.0538 acre.

**What is 100 km² in acres?**
100 km² = 24,710.538 acre.

**Is this conversion exact?**
Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit.

**Can I convert to other units on this page?**
This page converts only between square kilometres and acres. To pick any area unit, use the general area converter linked under Related calculators.

**What formula does the Square Kilometers to Acres Converter use?**
1 km² = 247.10538 acre.


## Sources

- [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)