PPM to NPK Weight

Calculate fertilizer weight needed for target PPM.

Verified ToolUpdated: January 10, 2026
Input Parameters
Calculated Result
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Weight Needed (g)

Methodology & Sources

To find the mass required: Mass = (Target PPM * Volume) / (Percent Concentration * 10,000). But since we use Percent as a whole number (e.g. 20), we adjust the factor.

The underlying formula used is:

(Target * Vol) / (Percent * 10)

References

  • Hydroponics Formulas

Frequently Asked Questions

How much fertilizer do I need?

It depends on the concentration. Example: To get 100 PPM N from a 20% N fertilizer in 100L: (100 * 100) / (20 * 10) = 50 grams.

Why divide by Percent * 10?

Because 1% in 1 Liter = 10,000 PPM. So a 1% fertilizer raises 10g/L to 10,000 PPM... the math simplifies to the factor of 10.
Vijay Chauhan

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