About the lawn fertilizer calculator
Lawn recommendations are usually written as pounds of actual nitrogen per 1,000 square feet, but fertilizer bags list a percentage. A 24-0-6 product is 24% nitrogen, so you need more than four pounds of product to apply one pound of nitrogen.
This calculator does that conversion. It doesn’t choose a rate for you — use the rate on your product label or from your local extension service.
How to use this calculator
- Enter your lawn area.
- Enter the nitrogen you plan to apply per application, from your label or local guidance.
- Enter the first number of the fertilizer analysis (N).
- Optionally enter bag weight and price for a bag count and cost.
Worked examples
- Target 1 lb N per 1,000 sq ft, product 24-0-6.
- 5 × 1 ÷ 0.24 = 20.8 lb of product
- A 15 lb bag covers 15 × 0.24 ÷ 1 × 1,000 = 3,600 sq ft
About 20.8 lb — two 15 lb bags.
Measurement guidance
Read the analysis
The three numbers on a fertilizer bag are the percentages of nitrogen (N), phosphate (P₂O₅), and potash (K₂O), always in that order.
Calibrate your spreader
Spreader settings on the bag are a starting point. Applying half the product in each of two perpendicular passes helps avoid stripes.
Frequently asked questions
How much nitrogen should I put on my lawn?
It depends on grass type, season, and local guidance. Many programs apply between about 0.5 and 1 lb of nitrogen per 1,000 sq ft per feeding, but always follow your product label and local regulations.
What does 24-0-6 mean?
The product contains 24% nitrogen, 0% phosphate, and 6% potash by weight.
Are there rules about lawn fertilizer?
Many states and municipalities restrict phosphorus, application near water, or application during certain months. Check local rules before applying.