How to read fertilizer labels?

N-P-K numbers are percentages. 10-10-10 means 10% each nutrient by weight.

Calculate lbs of product needed = (desired nutrient rate × area) / % nutrient in bag.

Fertilizer Rate Calculator

Calculate the total amount of fertilizer product needed based on your area and the desired nutrient application rate.

Calculate how much fertilizer product to apply based on a desired nutrient rate (typically Nitrogen).

Garden Area (sq ft)

Desired Rate (lbs N / 1000 sq ft)

Fertilizer's N Value (%)

The full supporting guide for this calculator is still being expanded. The tool remains accessible while we improve the educational content.

Continue with calculators that answer nearby questions and help compare the next step.

Calculate the actual weight of Nitrogen (N), Phosphorus (P), and Potassium (K) in a bag of fertilizer based on its NPK ratio.

Calculate the correct amount of liquid fertilizer concentrate to add to your watering can based on the desired mixing ratio.