About this calculator

How-to: enter field size (hectares) and the recommended nutrient rate for the crop in kg/ha of N, P₂O₅ and K₂O. Enter the analysis of your bagged fertilizer (e.g. 20-10-10 means 20% N, 10% P₂O₅, 10% K₂O). We compute nutrient demand, then the number of 50 kg bags required to hit the limiting nutrient — showing the surplus of the other two.

Frequently asked questions

Are my nutrient targets right?

Base them on a recent soil test and the crop's removal rate. Cereals ~120 kg N/ha, potatoes ~180 kg N/ha, grassland ~200 kg N/ha are common EU starting points.

Why do I get a surplus on P or K?

A single blend rarely matches all three targets exactly. The calculator sizes bags to the limiting nutrient — top up the other two separately with straights (urea, TSP, MOP) instead of buying more blend.

Does this cover organic amendments?

Not directly. Convert manure/compost to N-P-K equivalents first (e.g. FYM ≈ 6-3-8 kg/t) and enter that blend.

What does the Crop Nutrient & Fertilizer Mix Calculator do?

Kilograms of N, P₂O₅ and K₂O required for your field — and the bag count for a chosen NPK blend. How-to: enter field size (hectares) and the recommended nutrient rate for the crop in kg/ha of N, P₂O₅ and K₂O. Enter the analysis of your bagged fertilizer (e.g. 20-10-10 means 20% N, 10% P₂O₅, 10% K₂O). We compute nutrient demand, then the number of 50 kg bags required to hit the limiting nutrient — showing the surplus of the other two.

Is the Crop Nutrient & Fertilizer Mix Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Crop Nutrient & Fertilizer Mix Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified agriculture & farming professional before committing to a purchase or a job.

What inputs does the Crop Nutrient & Fertilizer Mix Calculator need?

Enter values for: Field size (ha), N target (kg/ha), P₂O₅ target (kg/ha), K₂O target (kg/ha), Blend %N, Blend %P₂O₅. Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Crop Nutrient & Fertilizer Mix Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.