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Lawn Fertilizer Calculator

How many pounds of product your lawn needs.

Enter your values

Results update instantly as you type — no submit needed.

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

  1. 1Measure your lawn area in square feet.
  2. 2Read the first number of the NPK analysis on the bag.
  3. 3Set your target nitrogen rate.

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.