Fertilizer Nutrient Calculator for N, P, K, Ca, Mg and S
Calculate fertilizer application rates for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). Estimate fertilizer requirements per hectare and total quantities by field area.
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Home » Fertilizer Nutrient Calculator
Nitrogen Fertilizer Application Rate Calculator
Calculate fertilizer requirements based on your target nitrogen rate, fertilizer grade, and field area. Results update automatically.
Enter the target amount of nitrogen required per hectare.
Select the fertilizer grade or enter a custom nitrogen percentage.
CALCULATED FERTILIZER RATE
217.39 kg/haFertilizer product required per hectare.
TOTAL FERTILIZER REQUIRED
2.174 metric tonsTotal product required for the selected area.
Formula: Fertilizer rate (kg/ha) = Required N rate (kg N/ha) ÷ (N content (%) ÷ 100). Total fertilizer (metric tons) = Fertilizer rate × field area ÷ 1,000.
Important: Fertilizer grades are nominal examples. Confirm the guaranteed analysis on the actual product label. Ammonium sulfate also supplies sulfur, while ammonium chloride supplies chloride. Consider these additional nutrients and ions when planning fertilizer applications.
Phosphorus Fertilizer Application Rate Calculator
Calculate fertilizer requirements based on your target P₂O₅ rate, fertilizer grade, and field area. Results update automatically.
Enter the target amount of P₂O₅ required per hectare.
Use the guaranteed P₂O₅ percentage stated on the product label.
CALCULATED FERTILIZER RATE
227.27 kg/haFertilizer product required per hectare.
TOTAL FERTILIZER REQUIRED
2.273 metric tonsTotal product required for the selected area.
Formula: Fertilizer rate (kg/ha) = Required P₂O₅ rate (kg/ha) ÷ (P₂O₅ content (%) ÷ 100). Total fertilizer (metric tons) = fertilizer rate × field area ÷ 1,000.
Important: This is a mathematical estimate, not a crop-specific recommendation. DAP, MAP, and UP also supply nitrogen; include that nitrogen in your nutrient budget. Confirm the actual guaranteed analysis on the product label.
Potassium Fertilizer Application Rate Calculator
Calculate fertilizer requirements based on your target K₂O rate, fertilizer grade, and field area. Results update automatically.
Enter the target amount of K₂O required per hectare.
Use the guaranteed K₂O percentage stated on the product label.
CALCULATED FERTILIZER RATE
166.67 kg/haFertilizer product required per hectare.
TOTAL FERTILIZER REQUIRED
1.667 metric tonsTotal product required for the selected area.
Formula: Fertilizer rate (kg/ha) = Required K₂O rate (kg/ha) ÷ (K₂O content (%) ÷ 100). Total fertilizer (metric tons) = fertilizer rate × field area ÷ 1,000.
Important: This is a mathematical estimate, not a crop-specific recommendation. MOP supplies chloride, SOP supplies sulfur, and potassium nitrate also supplies nitrogen. Account for these additional nutrients when planning fertilizer applications, and confirm the actual product analysis.
Calcium Fertilizer Application Rate Calculator
Calculate the amount of calcium fertilizer needed based on your target Ca rate, product content, and field area.
Enter the target amount of elemental calcium per hectare.
Typical values are shown; check the actual product label.
CALCULATED FERTILIZER RATE
210.53 kg/haProduct required per hectare.
TOTAL FERTILIZER REQUIRED
2.105 metric tonsTotal product for the selected area.
Formula: Fertilizer rate (kg/ha) = Required Ca rate (kg Ca/ha) ÷ (Ca content (%) ÷ 100). Total fertilizer (metric tons) = fertilizer rate × field area ÷ 1,000.
Important: Calcium nitrate also supplies nitrogen. Lime materials can change soil pH and are not interchangeable with soluble calcium fertilizers. Use soil-test recommendations and the actual product analysis.
Magnesium Fertilizer Application Rate Calculator
Calculate magnesium fertilizer requirements using your target Mg rate, product content, and field area.
Enter the target amount of elemental magnesium per hectare.
Typical elemental Mg values; confirm the actual product label.
CALCULATED FERTILIZER RATE
117.65 kg/haProduct required per hectare.
TOTAL FERTILIZER REQUIRED
1.176 metric tonsTotal product for the selected area.
Formula: Fertilizer rate (kg/ha) = Required Mg rate (kg Mg/ha) ÷ (Mg content (%) ÷ 100). Total fertilizer (metric tons) = fertilizer rate × field area ÷ 1,000.
Important: Magnesium oxide and dolomitic lime have different solubility and soil-pH effects from soluble magnesium sulfate products. This calculator estimates product mass only; it does not predict how quickly nutrients become plant-available.
Sulfur Fertilizer Application Rate Calculator
Calculate sulfur fertilizer requirements using your target S rate, product content, and field area.
Enter the target amount of elemental sulfur per hectare.
Typical sulfur percentages; confirm the guaranteed analysis on the product label.
CALCULATED FERTILIZER RATE
125.00 kg/haProduct required per hectare.
TOTAL FERTILIZER REQUIRED
1.250 metric tonsTotal product for the selected area.
Formula: Fertilizer rate (kg/ha) = Required S rate (kg S/ha) ÷ (S content (%) ÷ 100). Total fertilizer (metric tons) = fertilizer rate × field area ÷ 1,000.
Important: Ammonium sulfate also supplies nitrogen; SOP supplies potassium; magnesium sulfate supplies magnesium; gypsum supplies calcium. Elemental sulfur generally requires microbial oxidation before becoming available as sulfate, so its timing and availability differ from sulfate fertilizers.
