🌱Fertilizer Calculator
Find how many pounds and bags of fertilizer your lawn needs from the N-P-K numbers.
Your lawn
You'll need about
20.8 lb of product
2 bags of 15 lb · 4.17 lb per 1,000 sq ft
lb product
20.8
bags
2
lb nitrogen
5.00
lb phosphate
0.00
lb potash
1.25
🛒 Shopping list
- Fertilizer 24-0-6 (15 lb bags)2 bags
The three numbers on the bag are N-P-K percentages. Most lawns need about 1 lb of nitrogen per 1,000 sq ft per feeding.
How it works
Product (lb) = nitrogen rate ÷ (N% ÷ 100) × lawn area ÷ 1,000. Bags = product ÷ bag weight. The P and K numbers show how much phosphate and potash you apply along the way.
Worked example
A 5,000 sq ft lawn with 24-0-6 fertilizer at 1 lb of nitrogen per 1,000 sq ft: 1 ÷ 0.24 × 5 = 20.8 lb of product, or 2 bags of 15 lb.
Questions people ask
Percent nitrogen (N), phosphate (P) and potash (K) by weight.
More calculators you might like
Email me my results
Pop in your email and keep your numbers handy at the store.
Last updated October 8, 2026. These results are friendly estimates to help you plan — always double-check before buying or making big decisions.