Verification: factors follow standard unit definitions; round for display only.

Acres to square kilometers

Convert acres to km² when US deed acreage, farm reports, or county GIS layers list acres but international basemaps, metric environmental studies, or cross-border land comparisons expect square kilometers.

Acres and square kilometers both measure land area through the shared square-meter catalog. One acre equals 4,046.8564224 m² and one square kilometer equals 1,000,000 m², giving:

square kilometers = acres × 0.0040468564224  ·  equivalently   square kilometers = acres ÷ 247.105381467

Multiplying by 0.0040468564224 is preferred for catalog-exact results. About 247.1 acres fill one square kilometer.

Step-by-step conversion (worked example 1)

Convert 1 acre to square kilometers:

1. Write the formula: km² = acres × 0.0040468564224
2. Multiply: 1 × 0.0040468564224 = 0.0040468564224 km²
3. Display: 0.00405 km² on a metric land summary

Step-by-step conversion (worked example 2)

Convert 247.105 acres to square kilometers—approximately one sq km:

1. 247.105 × 0.0040468564224 ≈ 1.000 km²
2. Exact bridge: 1 km² = 247.105381467 ac

Step-by-step conversion (worked example 3)

Convert 640 acres (one section) to square kilometers:

1. 640 × 0.0040468564224 = 2.589988110336 km²
2. Compare: one sq mi = 2.590 km² (same value via sq mi route)

Quick mental estimate (no calculator)

Divide acres by 250 for a quick km² estimate (about 1.2% low). Example: 500 ac ÷ 250 = 2 km² (exact: 2.023 km²). Use 0.0040468564224 when reconciling metric GIS overlays with deed acreage.

Acres to square kilometers conversion chart

Where acres → km² comes up

• Cross-border land comparison: US listings quote acres; Canadian and European references use km². Convert before comparing ranch sizes or conservation holdings.
• Metric GIS basemaps: Legacy US parcel layers store acres; SI environmental impact studies and global datasets expect km².
• Wildlife & habitat studies: Species home-range literature often cites km²; US field surveys report acres. Align units before density calculations.
• Energy & infrastructure: Pipeline right-of-way and solar farm footprints may be dimensioned in km² on international engineering specs while local leases list acres.

Square kilometers to acres

Convert km² to acres when a metric atlas, satellite-derived land cover map, or international report lists square kilometers but US tax rolls, farm leases, or deed descriptions quote acres.

Reverse the acre-to-km² relationship. Because 1 km² = 1,000,000 m² and 1 acre = 4,046.8564224 m², one square kilometer equals 247.105381467… acres.

acres = square kilometers × 247.105381467  ·  equivalently   acres = square kilometers ÷ 0.0040468564224

Step-by-step conversion (worked example)

Convert 2.59 km² to acres—approximately one square mile:

1. Write the formula: ac = km² × 247.105381467
2. Multiply: 2.59 × 247.105381467 ≈ 640 ac
3. Exact: 2.589988110336 km² = 640 ac (one section)

Quick reference (km² → ac)

Reverse conversion is essential when importing km² boundaries from global land-cover datasets into county GIS layers that store parcel acreage.

Acres vs square kilometers, common mistakes, and related tools

Both directions share catalog-exact factors. Avoid shortcut errors and verify with anchor parcels before publishing land totals.

Acres vs square kilometers at a glance

Common mistakes to avoid

• Using 0.004 or 250 as exact factors—fine for mental math (~1–2% error), but use 0.0040468564224 and 247.105381467 for GIS reconciliation.
• Confusing km² with hectares—1 km² = 100 ha = 247.1 ac. A 10 km² reserve is 2,471 ac, not 10 ac.
• Multiplying when you should divide—ac → km² means multiply by 0.0040468564224; km² → ac means multiply by 247.105381467.

Related area converters

For the inverse of this page, open square kilometers to acres. Nearby workflows: acres to hectares, acres to square miles, and square kilometers to hectares.