Lawn Fertilizer Calculator
How many pounds of product your lawn needs.
Enter your values
ⓘ Live results
Results
- Fertiliser needed
- 20.83 lb
- Per 1,000 sq ft
- 4.17 lb
- Nitrogen applied
- 5 lb
- 50 lb bags needed
- 0.42
Quick answer
Pounds of product = target lb of nitrogen per 1,000 sq ft × lawn area ÷ 1,000 ÷ the nitrogen percentage.
lb product = (N rate × area ÷ 1000) ÷ (N% ÷ 100)
How to use the Lawn Fertilizer Calculator
- 1Measure your lawn area in square feet.
- 2Read the first number of the NPK analysis on the bag.
- 3Set your target nitrogen rate.
Worked example
Using the values the calculator loads with:
Inputs
- Lawn size5000 sq ft
- Nitrogen in the bag24 %
- Target nitrogen rate1 lb per 1000 sq ft
Results
- Fertiliser needed20.83 lb
- Per 1,000 sq ft4.17 lb
- Nitrogen applied5 lb
- 50 lb bags needed0.42
Frequently asked questions
What is a typical nitrogen rate?
1 lb of nitrogen per 1,000 sq ft per application, with 3–4 lb total per year for cool-season grass.
What do the three NPK numbers mean?
Percentages by weight of nitrogen, phosphorus and potassium — 24-0-6 means 24% nitrogen and no phosphorus.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.