Fertiliser Rate Per Hectare
Calculator

It typically refers to the amount of the fertiliser product itself (e.g., kg of urea) rather than the pure nutrient it contains. To know the actual nitrogen, phosphorus, or potassium delivered, you still need to apply the product's nutrient analysis percentage.

Divide the recommended nutrient amount (say, kg N/ha) by the fraction of that nutrient in your chosen product (e.g., 46% for urea) to get the product application rate. Skipping this conversion is the most common source of under- or over-fertilising.

Soil tests reveal how much of a nutrient is already available, so the fertiliser rate should only make up the shortfall between what the crop needs and what the soil already supplies. Applying a blanket rate without a soil test risks wasting money or under-feeding the crop.

For mobile nutrients like nitrogen, splitting the total rate across two or three applications usually reduces leaching losses and matches uptake better than one large dose. Less mobile nutrients like phosphorus are more commonly applied all at once at or before planting.

No — the calculation only converts your target rate into a quantity for your area. Any nutrient credit from manure, compost, or a preceding legume needs to be subtracted from the recommendation before you calculate the product rate.