Fertilizer Calculation Guide: NPK, Urea, and More

Fertilizer recommendations are given in kg of pure nutrient (N, P₂O₅, or K₂O) per feddan. To find how much actual fertilizer to apply, divide by the nutrient percentage.

Common fertilizers: Urea (46% N), Ammonium nitrate (33.5% N), Ammonium sulfate (20.6% N), Single superphosphate (15% P₂O₅), Triple superphosphate (46% P₂O₅), DAP (18% N, 46% P₂O₅), MOP (60% K₂O), SOP (50% K₂O).

Example: If the recommendation is 80 kg N per feddan and you use urea (46% N): Fertilizer needed = 80 / 0.46 = 173.9 kg urea per feddan.

For 5 feddans: 173.9 × 5 = 869.6 kg total. In 50 kg bags: 869.6 / 50 = 17.4 → 18 bags.

Typical N recommendations (kg/feddan): Wheat 60-80, Corn 120-150, Cotton 80-100, Rice 70-90, Potato 100-120. Split application is recommended for better efficiency.

Use our Fertilizer Calculator in the Agriculture category — it supports feddan/acre/hectare, 9 fertilizer types, and calculates bags needed.