---
title: "Fertilizer NPK calculator"
description: "Enter fertilizer N-P-K percentages, pick a nutrient, and set your desired rate and lawn area to see how much product you need."
slug: npk
canonical: "https://lawncarejournal.app/tools/npk/"
markdownMirror: "https://lawncarejournal.app/tools/npk.md"
---

# Fertilizer NPK calculator

Enter fertilizer N-P-K percentages, pick a nutrient, and set your desired rate and lawn area to see how much product you need.

## Summary

Convert a desired nutrient rate into how much fertilizer product to apply.

## Disclaimer

Verify percentages on the product label. Results are math helpers only—follow the label and local extension guidance for timing and rates.

## How to use

Open the interactive calculator at https://lawncarejournal.app/tools/npk/. Results are estimates for DIY planning—verify product labels and local extension guidance before applying anything.

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