Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Nitrogen product (lb/acre)
347.8
Phosphate product (lb/acre)
130.4
Nitrogen product needed (tons)
27.83
Nitrogen cost
$14,470
Cost per pound of N
$0.565
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter nitrogen target (lb N/acre).
- 2Enter product nitrogen (%).
- 3Enter phosphate target (lb P₂O₅/acre).
- 4Enter product phosphate (%).
- 5Enter acres.
- 6Enter n product price ($/ton).
- 7Read your nitrogen product (lb/acre) on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Enter your nutrient targets and the analysis printed on the bag to get the product rate per acre, total tonnage, and cost per unit of nitrogen.
Worked example
Using the values the calculator loads with:
Inputs
- Nitrogen target: 160 lb N/acre
- Product nitrogen: 46 %
- Phosphate target: 60 lb P₂O₅/acre
- Product phosphate: 46 %
- Acres: 160
- N product price: 520 $/ton
Results
- Nitrogen product (lb/acre): 347.8
- Phosphate product (lb/acre): 130.4
- Nitrogen product needed (tons): 27.83
- Nitrogen cost: $14,470
- Cost per pound of N: $0.565
What each field means
Inputs
- Nitrogen target (lb N/acre)
- The nitrogen target used in the calculation, measured in lb N/acre. Starts at 160 lb N/acre so you have a working example on load.
- Product nitrogen (%)
- The product nitrogen used in the calculation, measured in %. Starts at 46 % so you have a working example on load. Accepted range: 1–100 %.
- Phosphate target (lb P₂O₅/acre)
- The phosphate target used in the calculation, measured in lb P₂O₅/acre. Starts at 60 lb P₂O₅/acre so you have a working example on load.
- Product phosphate (%)
- The product phosphate used in the calculation, measured in %. Starts at 46 % so you have a working example on load. Accepted range: 1–100 %.
- Acres
- The acres used in the calculation. Starts at 160 so you have a working example on load.
- N product price ($/ton)
- The n product price used in the calculation, measured in $/ton. Starts at 520 $/ton so you have a working example on load.
Results
- Nitrogen product (lb/acre)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Phosphate product (lb/acre)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Nitrogen product needed (tons)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Nitrogen cost
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Cost per pound of N
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why compare cost per pound of N?
Bag prices are meaningless across analyses. Urea at 46% and UAN at 32% only compare once you price the actual nutrient.
Does this handle blends?
Run each nutrient separately, then have the retailer blend to the rates shown.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Fertilizer Blend & NPK Rate Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/fertilizer-blend
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/fertilizer-blend" target="_blank" rel="noopener">Fertilizer Blend & NPK Rate Calculator — RevenueLab</a> (2026).</p>
Source: [Fertilizer Blend & NPK Rate Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/fertilizer-blend) (2026).