N-P-K and fertilizer calculators. Browse our free fertilizer tools below — all calculators are instant, accurate, and require no sign-up.
Fertilizer Blend Calculator — Calculate the blend ratio of fertilizer products to hit target N-P-K rates. Optimize your custom blend for cost and nutrient balance.
Fertilizer Cost per Acre Calculator — Calculate total fertilizer cost per acre by summing product rates and prices. Compare blends and budgets for your crop nutrition program.
Foliar Feeding Rate Calculator — Calculate foliar fertilizer spray concentration, product rate per acre, and solution mix for tank sprayers. Avoid leaf burn with proper rates.
Manure Application Rate Calculator — Calculate manure application rate in tons per acre based on crop nutrient need, manure nutrient content, and availability percentage.
Manure Nutrient Value Calculator — Calculate the fertilizer replacement value of manure in dollars per ton based on N-P-K content and current fertilizer prices.
NPK Fertilizer Rate Calculator — Calculate the product application rate in lbs per acre from your nutrient need and fertilizer analysis percentage. Free online NPK rate tool.
Organic Fertilizer Equivalence Calculator — Calculate how much organic fertilizer equals a given amount of synthetic nitrogen based on organic N% and availability rate.
Precision Nutrient Map Calculator — Interpolate soil sample points into zone-based nutrient maps. Plan prescription rates from grid sampling for precision nutrient management.