Convert acre to square kilometer

1 ac = 0.004046856422 km²

1 ac = 0.00405 km²

1 ac in every area unit

square millimeter	4,050,000,000 mm²
square centimeter	40,500,000 cm²
square meter	4,050 m²
hectare	0.405 ha
square kilometer	0.00405 km²
square inch	6,270,000 in²
square foot	43,600 ft²
square yard	4,840 yd²
acre	1 ac
square mile	0.00156 mi²

How the conversion works

Multiply by 0.004046856422 to go from acre to square kilometer, or divide by it to go back. Every conversion on this site routes through the SI value (m²) rather than a table of pairwise factors, so a round-trip returns exactly what you started with.

Going the other way? square kilometer to acre — 1 km² = 247.1053815 ac.

acre to square kilometer — common values

1 ac	0.0040468564 km²
2 ac	0.0080937128 km²
3 ac	0.012140569 km²
5 ac	0.020234282 km²
10 ac	0.040468564 km²
15 ac	0.060702846 km²
20 ac	0.080937128 km²
25 ac	0.10117141 km²
50 ac	0.20234282 km²
75 ac	0.30351423 km²
100 ac	0.40468564 km²
250 ac	1.0117141 km²
500 ac	2.0234282 km²
1000 ac	4.0468564 km²

Other area conversions

mm² → km² cm² → km² m² → km² in² → km² ft² → km² yd² → km² ac → mm² ac → cm²

All area units →

Solvers that use area