Dry / Granular Fertilizer Calculator
Calculate exactly how much granular fertilizer you need. Enter your area (sq ft to hectare), select a fertilizer (10-10-10, Urea, DAP, MOP, SSP, or custom NPK), and set your target nutrient rate. Get results in lbs and kg, bags to buy, and total cost.
10% N · 10% P · 10% K
Click a field to set it as the primary nutrient for product calculation. Other nutrients are shown as targets.
Results
Nutrients Delivered
Granular Fertilizer Application Rates
| Fertilizer | N-P-K | Primary Use | Lbs/1,000 sqft (1 lb N) | Lbs/Acre (1 lb N) |
|---|---|---|---|---|
| 46-0-0 Urea | 46-0-0 | Pure N source | 2.17 lbs | 94.5 lbs |
| 21-0-0 Amm. Sulfate | 21-0-0 | Acidifying N | 4.76 lbs | 207.4 lbs |
| 18-46-0 DAP | 18-46-0 | Starter / High P | 5.56 lbs | 242 lbs |
| 0-46-0 TSP | 0-46-0 | Pure P source | — | — |
| 0-0-60 MOP | 0-0-60 | Pure K source | — | — |
| 10-10-10 All Purpose | 10-10-10 | Balanced garden | 10 lbs | 435.6 lbs |
| 12-12-12 Starter | 12-12-12 | New lawns/beds | 8.33 lbs | 362.9 lbs |
| 16-4-8 Lawn | 16-4-8 | Established lawn | 6.25 lbs | 272.3 lbs |
Rates at 1 lb N per 1,000 sq ft (109 kg N/ha). TSP and MOP rates depend on P/K target, not N.
Unit Conversion Reference
Frequently Asked Questions
How much granular fertilizer per 1,000 square feet?
Product per 1,000 sq ft = N rate ÷ (N% ÷ 100). For 10-10-10 (10% N) at 1 lb N: 1 ÷ 0.10 = 10 lbs/1,000 sq ft. For 46-0-0 Urea (46% N) at 1 lb N: 1 ÷ 0.46 = 2.17 lbs/1,000 sq ft. The lower the N%, the more product needed. Our calculator handles any NPK ratio and shows lbs and kg results.
How much 10-10-10 fertilizer per 1,000 square feet?
At 1 lb N per 1,000 sq ft: 10 lbs of 10-10-10 per 1,000 sq ft (since N% = 10%). This also delivers 10 lbs P and 10 lbs K per 1,000 sq ft simultaneously. For a 5,000 sq ft lawn: 10 × 5 = 50 lbs total. A 40 lb bag covers 4,000 sq ft. You'd need 2 bags (80 lbs) to cover 5,000 sq ft at 1 lb N rate.
How do I calculate dry fertilizer for an acre?
1 acre = 43,560 sq ft = 43.56 units of 1,000 sq ft. At 1 lb N per 1,000 sq ft with 10-10-10: 10 lbs/1,000 sqft × 43.56 = 435.6 lbs/acre. With 46-0-0 Urea: 2.17 × 43.56 = 94.5 lbs/acre. At the typical row-crop rate of 0.5 lb N/1,000 sqft: 217 lbs/acre of 10-10-10. Select 'Acre' in the area unit dropdown for direct calculation.
What is the difference between 10-10-10, 12-12-12, and 16-4-8 fertilizer?
10-10-10 and 12-12-12 are balanced all-purpose fertilizers — equal parts N, P, and K. Good for establishing new lawns or vegetable gardens. 16-4-8 has high N, low P, moderate K — better for established lawns that already have sufficient phosphorus (most do after a few years). Use 12-12-12 when starting a new lawn or garden bed; switch to 16-4-8 or 30-0-10 for maintenance.
How much Urea (46-0-0) fertilizer per acre?
Urea (46-0-0) is the most concentrated dry N fertilizer at 46% N. At 100 lbs N/acre (typical corn application): 100 ÷ 0.46 = 217 lbs Urea/acre. At 50 lbs N/acre (lawn application): 108.7 lbs Urea/acre. In kg/ha: 100 kg N/ha = 217 kg Urea/ha. Switch to 'kg/ha' rate unit in the calculator for metric calculations.
What is the fertilizer spreader setting for granular fertilizer?
Spreader settings vary by brand (Scotts, Earthway, Agri-Fab). Always check the fertilizer bag for brand-specific settings. As a starting point: a standard broadcast spreader at setting 4-5 (out of 10) typically delivers 3-5 lbs/1,000 sq ft. Use the calculator to get your target application rate in lbs/1,000 sq ft, then calibrate your spreader by weighing product caught over a measured area.
How do I convert fertilizer rate from kg/ha to lbs per 1,000 sq ft?
Formula: lbs/1,000 sqft = kg/ha × 0.009178. Example: 100 kg N/ha = 100 × 0.009178 = 0.92 lbs N per 1,000 sq ft. Reverse: kg/ha = lbs/1,000 sqft × 108.9. Our calculator has a built-in rate unit toggle — switch between lbs/1,000 sqft and kg/ha and it converts automatically.
How much DAP (18-46-0) fertilizer per acre?
DAP (18-46-0) is a common starter fertilizer with high phosphorus. At a typical P rate of 40 lbs P₂O₅ per acre: Product = 40 ÷ 0.46 = 86.9 lbs DAP/acre. This also delivers 86.9 × 0.18 = 15.6 lbs N/acre as a bonus. For a balanced crop program, supplement remaining N with Urea. The calculator lets you set P as the primary nutrient to calculate DAP quantity.