Agricultural Field Calculators
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Fertilizer Application Rate Calculator

Calculate pump settings, gallons per acre, and nutrient delivery for 40 liquid fertilizers including UAN 28/30/32, APP 10-34-0, KTS, ATS, 6-24-6, Sure-K, and liquid AMS. Use the Blend / Tank Mix tab to combine up to 6 products and see total N-P-K-S applied across your field.

Calculate fertilizer and pesticide application rates per acre and calibrate your injection pump. The Basic tab finds the percent pump setting needed to apply a target tank volume over a given field in your desired runtime. The Advanced tab calculates cost per acre, product per acre, and total product needed for single products or multi-product tank mixes. Used by farmers, applicators, and agronomists for spray planning and pump calibration.

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Fertilizer Rate Calculator

Find the correct pump setting to apply the right volume across your field in your target timeframe.

Enter your field size, total tank solution volume, pump size, and desired application time — get the required pump percent setting and key derived values.

Field
Tank Solution
Total volume of the ready-to-apply tank solution to inject across the whole field.
Pump
Maximum pump output when set to 100%.
Application Time
How long you want the full application to take.

Fill in the fields and press Calculate to see your pump setting.

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Disclaimer — Application rate calculations are for reference only. Always read and follow pesticide and fertilizer product labels, which are the legal document governing use. Application rates, carrier volumes, and restrictions vary by product, crop, and state. Verify compliance with applicable regulations.

Frequently Asked Questions

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Application rate is the amount of a product — fertilizer, herbicide, fungicide, or pesticide — applied per unit of land area. It's typically expressed in gallons per acre (GPA), ounces per acre (oz/ac), or pounds per acre. Getting application rate right matters for two reasons: too little and the product doesn't work; too much and you waste money, risk crop damage, and may violate label requirements. Sprayer calibration ensures the equipment delivers exactly the intended rate.

Gallons per acre = (lbs nutrient/acre ÷ nutrient fraction as decimal) ÷ product density (lbs/gal). For UAN 32 at 100 lbs N/acre: 100 ÷ 0.32 = 312.5 lbs ÷ 10.65 lbs/gal = 29.3 gal/acre.
UAN 32: 10.65 lbs/gal. UAN 28: 10.41 lbs/gal. 10-34-0 (APP): 11.65 lbs/gal. AMS solution: 11.04 lbs/gal. 0-0-60 liquid potash: 11.7 lbs/gal. Potassium thiosulfate (0-0-25-17S): 11.7 lbs/gal. Ammonium thiosulfate (12-0-0-26S): 10.8 lbs/gal.
UAN 32: 32% N, 10.65 lbs/gal. UAN 28: 28% N, 10.41 lbs/gal. UAN 28 has a lower salt index and reduced foliar burn risk, making it preferred for in-season applications near crop canopy. UAN 32 is more economical per lb of N for soil applications.
Use the tank mix tab — add up to 6 products and enter gal/acre for each. The calculator shows combined N-P₂O₅-K₂O-S per acre, total cost per acre, combined tank volume, and pump settings. Always verify product compatibility before mixing.
Injection rate (gal/min) = (gal/acre target × pivot GPM) ÷ (acres × 60). For 3 gal/acre UAN on a 125-acre pivot at 1,000 GPM: 3 × 1,000 ÷ (125 × 60) = 0.4 gal/min injected.
Many chelated micronutrients (zinc EDTA, manganese EDTA) are compatible with UAN in diluted concentrations. Always perform a jar test first: combine proportional amounts, shake, and observe for precipitation over 30 minutes before tank loading.

Gallons per acre (GPA) = (nozzle output in oz/min × 5,940) ÷ (speed in mph × nozzle spacing in inches). For example: 20 oz/min × 5,940 ÷ (7 mph × 20 inches) = 8.49 GPA. Most herbicide applications run 5–15 GPA depending on the product label requirements.

Tank mix compatibility verifies that multiple pesticides can be physically combined without precipitation, crystallization, or chemical breakdown. The general jar test mixes products in a small container in the intended order — water first, then dry flowables, wettable powders, emulsifiable concentrates — and observes for separation, clumping, or heat. Always check label restrictions before mixing products.