Square Decimeters to Hectares: the quick answer
1 dm² = 1 × 10⁻⁶ ha
1 square decimeter equals 1 × 10⁻⁶ hectares
To convert square decimeters to hectares, multiply the value by 1 × 10⁻⁶. To go the other way, multiply hectares by 1,000,000 to get square decimeters.