Fertilizer Calculator
Calculate how much fertilizer to apply based on garden area and desired nitrogen application rate.
How It Works
Enter your garden area, desired nitrogen application rate (typically 1-2 lbs per 1000 sq ft), and the nitrogen percentage on your fertilizer bag. The calculator returns pounds of fertilizer to apply.
Formula
Fertilizer (lbs) = (Area sq ft x N Rate lbs/1000) / (N% / 100) / 10
Frequently Asked Questions
How much nitrogen does my garden need?
Most vegetables need 1-2 lbs of actual nitrogen per 1000 sq ft per season. Heavy feeders like corn and tomatoes may need more. Always test your soil first.
What does the first number on a fertilizer bag mean?
The three numbers on a fertilizer bag represent NPK: Nitrogen (N), Phosphorus (P), and Potassium (K) percentages by weight. A 10-10-10 bag is 10% nitrogen.