Square Kilometer to Acre (km² to ac)
Result
247.1053815 Acre
Formula
ac = km² × 247.1053815
1 km² = 247.1053815 ac, and 1 ac = 0.004046856422 km².
Area factors are the square of the length factor: 1 ft = 0.3048 m, so 1 ft² = 0.3048² = 0.09290304 m². The acre is 43,560 ft² (4,046.8564224 m²) and the hectare 10,000 m².
Worked examples
- 1 km² × 247.1053815 = 247.10538 ac
- 10 km² × 247.1053815 = 2,471.0538 ac
- 100 km² × 247.1053815 = 24,710.538 ac
Common mistakes
- Do not apply a length factor to an area: 100 m² is 1,076.39 ft², not 328 ft² (100 × 3.28).
- A plot described as "20 × 30 ft" is 600 ft²; convert each side to metres first or convert the area afterwards — never just one side.
Square Kilometer to Acre table
| Square Kilometer (km²) | Acre (ac) |
|---|---|
| 1 | 247.10538 |
| 2 | 494.21076 |
| 5 | 1,235.5269 |
| 10 | 2,471.0538 |
| 20 | 4,942.1076 |
| 50 | 12,355.269 |
| 100 | 24,710.538 |
| 1,000 | 247,105.38 |
The units
- Square Kilometer (km²)
- 1 Square Kilometer = 1,000,000 Square Meter.
- Acre (ac)
- 43,560 square feet, exactly 4,046.8564224 m². 640 acres make a square mile.
Sources for these factors
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy