🌾 Fertilizer Calculator
Convert nutrient requirements into fertilizer product rates for lawns, gardens, or farm fields.
Fertilizer grade (N-P-K)
Target nutrients (lb per 1,000 sq ft)
Set P and K to 0 if only nitrogen is targeted.
How to Use This Calculator
Test your soil
Use lab results to determine nutrient needs and application timing.
Enter fertilizer grade
Use the N-P-K values listed on the product bag (e.g., 24-5-11).
Apply uniformly
Use a calibrated spreader to deliver the calculated pounds evenly.
Formula
Product (lb) = (Area × Target N ÷ 1000) ÷ (N% ÷ 100)
N Applied = Product × (N% ÷ 100) ÷ Area × 1000
P and K applications follow the same logic. Adjust rates to prevent over-application if soil tests show high levels.
Full Description
Balancing nutrients improves turf vigor, crop yield, and plant health. Use this calculator alongside soil tests to avoid excess runoff and meet environmental regulations.
Split applications and slow-release products can reduce burn risk and provide season-long nutrition.
Frequently Asked Questions
What if I only need nitrogen?
Set target P and K to zero. Choose a high-nitrogen product to meet the requirement efficiently.
How often should I fertilize?
Follow regional guidelines—cool-season turf often gets 3–4 applications per year; crops vary by growth stage.
Can I mix different fertilizers?
Yes, but calculate each product separately and ensure compatibility before blending.
What about organic fertilizers?
Use the guaranteed analysis on organic labels. Nutrient release may be slower, so adjust timing accordingly.