🌿 NPK Fertilizer Calculator
How much fertilizer to apply by NPK ratio and bed size
About this calculator
The NPK Fertilizer Calculator decodes the three numbers on a fertilizer bag. Enter the N-P-K percentages and application rate; it converts them into actual pounds of nitrogen, phosphorus, and potassium per 1,000 square feet, and compares products by cost per pound of nutrient. Two bags with different NPK numbers can deliver identical nitrogen at very different prices.
Tip: buy for the nutrient you actually need — a soil test beats the bag's marketing, and excess phosphorus mostly washes into waterways.