NPK Requirement Calculator
Enter yield and separate removal and supply values for N, P2O5, and K2O; each requirement is calculated in this browser.
A QUICK WALKTHROUGH
How to use this tool
- Enter yield in t/ha.
- Enter removal in kg/t and soil supply in kg/ha separately for N, P2O5, and K2O.
- Review max(0, yield × removal − supply) in kg/ha for each nutrient.
Units and assumptions
Use N, P2O5, and K2O consistently; elemental P and K are not interchangeable with P2O5 and K2O. You provide all inputs; no crop or fertilizer rate is assumed.
Limits and local processing
Results are estimates, not agronomic advice or fertilizer recommendations. Follow product labels, required personal protective equipment (PPE), and local regulations when handling fertilizer. Values are calculated in this browser.
GOOD TO KNOW
Common questions
Does this recommend an NPK product or application rate?
No. It estimates each nutrient separately from the values you enter; it does not choose a product or a fertilizer application rate.
What if soil supply exceeds yield × removal?
The requirement for that nutrient is zero.