Fertilizer N-P-K Mixer
Mix fertilizers to achieve your target N-P-K ratio. Enter your target ratio and available fertilizers to calculate exact mixing proportions.
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Applications
Used by home gardeners blending custom N-P-K ratios from bagged fertilizers, small-scale farmers optimizing fertilizer cost by mixing cheaper sources, and hydroponic growers preparing stock solutions with precise elemental targets.
The Mixing Math
For 2 fertilizers, the system solves a simple ratio: target_N / target_P = (n1 × w1 + n2 × w2) / (p1 × w1 + p2 × w2). For 3 fertilizers, Cramer's rule solves the 3×3 linear system simultaneously. The weights are normalized so w1 + w2 + w3 = total_mass. If the target is infeasible (e.g., wanting 20% N from fertilizers that contain no N), the calculator flags it instead of returning a meaningless blend.
Fun Fact: Lawn fertilizers like 30-0-4 (30% N, 0% P, 4% K) are designed for quick green-up without stimulating top growth or root burn. The N-P-K ratio you choose dramatically affects plant behavior — high N for leafy greens, high P for blooms, high K for fruiting.
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