Fertilizer calculator for turf (lb N per 1,000 ft²)
You know the nitrogen rate you want; the bag only tells you its analysis. A fertilizer calculator works out how much product to spread per 1,000 ft² to hit that rate, how much you need for the whole area, and how many bags to order.
Free to use. No sign-up, no email.
Results
- Product rate
- 4.17 lb/1,000 ft²
- Total product
- 907.5 lb
- Bags needed (rounded up)
- 19
- P₂O₅ applied
- 0 lb/1,000 ft²
- K₂O applied
- 0.46 lb/1,000 ft²
- Total N applied
- 217.8 lb
Always follow the product label.
The formula behind the fertilizer calculator
Product rate
lb product per 1,000 ft² = lb N per 1,000 ft² ÷ (N % ÷ 100)
Total product and bags
total = product rate × area (ft²) ÷ 1,000 · bags = total ÷ bag weight, rounded up
Phosphate and potash that come along
P₂O₅ = product rate × P₂O₅ % ÷ 100 · K₂O = product rate × K₂O % ÷ 100
Metric
1 g per m² = 0.2048 lb per 1,000 ft² · 1 acre = 43,560 ft²
Derived from the exact pound and foot definitions below.
Where the numbers come from
- Fertilizer needed from the nitrogen rate, and what the bag numbers mean: lb of fertilizer per 1,000 ft² = lb N per 1,000 ft² × 100 ÷ % N; the grade is % N, % P₂O₅, % K₂O by weight. Virginia Cooperative Extension 430-011, “Lawn Fertilization in Virginia”
- Independent worked example: 2 lb N per 1,000 ft² from a 30-0-0 product is 6.66 lb of product per 1,000 ft². University of Delaware Cooperative Extension, “Commercial Nutrient Handler Calculation Review”
- Pound, foot and acre: 1 lb = 453.59237 g, 1 ft = 0.3048 m, 1 acre = 43,560 ft² (all exact). NIST Handbook 44 (2024), Appendix C
Worked example (the calculator opens with these numbers)
- Goal: 1 lb N per 1,000 ft² from a 24-0-11 product in 50 lb bags, over 5 acres.
- Area: 5 × 43,560 = 217,800 ft².
- Product rate: 1 ÷ 0.24 = 4.17 lb of product per 1,000 ft².
- Total product: 4.1667 × 217.8 = 907.5 lb.
- Bags: 907.5 ÷ 50 = 18.15, so 19 bags.
- Potash that comes with it: 4.1667 × 0.11 = 0.46 lb K₂O per 1,000 ft².
Second check from the sources: 2 lb N per 1,000 ft² from 30-0-0 is 6.67 lb of product per 1,000 ft² (the extension sheet rounds it to 6.66).
Questions about the fertilizer calculator
How do I work out how much fertilizer to apply?
Divide the pounds of nitrogen you want per 1,000 ft² by the nitrogen percentage written as a decimal. For 1 lb N from a 24-0-11 product, 1 ÷ 0.24 = 4.17 lb of product per 1,000 ft².
What do the three numbers on a fertilizer bag mean?
The three numbers on a fertilizer bag are the percent by weight of nitrogen (N), phosphate (P₂O₅) and potash (K₂O) in the product.
Why does the fertilizer calculator round the bag count up?
The fertilizer calculator rounds up because you can't buy part of a bag; rounding down would leave part of the area short.
Does the fertilizer calculator tell me how much nitrogen my turf needs?
No. The fertilizer calculator converts a nitrogen rate you choose into product. The rate itself comes from your soil test, your agronomist and the product label.
Get this for your actual course
Atlas maps every green, tee and fairway on your course with its area, so the area you type here comes from your own ground. Areas are approximate.
Questions? info@aetherisintel.com