Hectares to Square Mils: the quick answer
1 ha = 15,500,000,000,000 mil²
1 hectare equals 15,500,000,000,000 square mils
To convert hectares to square mils, multiply the value by 15,500,000,000,000. To go the other way, multiply square mils by 6.4516 × 10⁻¹⁴ to get hectares.