Square Kilometers to Acres Converter
Convert square kilometers to acres — multiply by 247.1. Results update as you type; exact factors shown.
One square kilometer is 247.1054 acres — see the exact factor, not a rounded rule of thumb.
How the square kilometers to acres converter works
Areas convert through the square meter. Because the inch is exactly 25.4 mm, a square foot is exactly 0.09290304 m², an acre (43,560 square feet) is exactly 4,046.8564224 m² and a square mile (640 acres) is 2,589,988.110336 m². A hectare is 10,000 m² by definition.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common area conversions
| From | To | Units |
|---|---|---|
| 0.01 km² | 2.4711 ac | square kilometers to acres |
| 0.1 km² | 24.7105 ac | square kilometers to acres |
| 0.4047 km² | 100.0035 ac | square kilometers to acres |
| 0.5 km² | 123.5527 ac | square kilometers to acres |
| 1 km² | 247.1054 ac | square kilometer to acres |
| 2 km² | 494.2108 ac | square kilometers to acres |
| 2.59 km² | 640.0029 ac | square kilometers to acres |
| 5 km² | 1,235.5269 ac | square kilometers to acres |
| 10 km² | 2,471.0538 ac | square kilometers to acres |
| 50 km² | 12,355.2691 ac | square kilometers to acres |
| 100 km² | 24,710.5381 ac | square kilometers to acres |
| 1,000 km² | 247,105.3815 ac | square kilometers to acres |
Units in this converter and their exact factors
| Unit | Symbol | One unit in square meters |
|---|---|---|
| square millimeter | mm² | 0.000001 square meter |
| square centimeter | cm² | 0.0001 square meter |
| square meter | m² | 1 square meter |
| hectare | ha | 10,000 square meter |
| square kilometer | km² | 1,000,000 square meter |
| square inch | in² | 0.00064516 square meter |
| square foot | ft² | 0.09290304 square meter |
| square yard | yd² | 0.83612736 square meter |
| acre | ac | 4,046.8564224 square meter |
| square mile | mi² | 2,589,988.110336 square meter |
FAQFrequently asked questions about area conversion
How many acres in a square kilometer?
247.105.
What is 2.59 km²?
One square mile, or 640 acres.
How does a hectare compare?
A hectare is 2.471 acres, and there are 100 hectares in a square kilometer.
Which do land titles use?
Acres in the US and in older UK and Australian titles; hectares in modern metric registration.
What is 1 km² in hectares?
Exactly 100.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.