Fertilizer Cost Comparison Calculator
Per-unit nutrient cost across fertilizer sources.
About this calculator
Bag price and bulk price rarely tell you which fertilizer is the better deal — a $520/ton bag of 46% urea and a $380/ton tank of 32% UAN look like they're comparing apples to oranges until you convert both to cost per pound of actual nutrient. This calculator does that conversion directly: cost per lb of nutrient = price per unit divided by (unit weight × analysis% ÷ 100), which strips away bag size and price-per-ton noise to leave the one number that matters agronomically. From there it works out how many pounds of each product you'd need per acre to hit your target nutrient rate (target lbs nutrient ÷ analysis% ÷ 100), multiplies by price per pound of product to get cost per acre, and scales both up by your field size to show total cost and tonnage for the whole operation.
The side-by-side savings figure — in both dollars and percentage — comes straight from the difference between the two products' cost-per-acre totals at the same target nutrient rate, so it's a true apples-to-apples comparison even when the two products have very different analyses. The biggest input trap is unit weight: dry granular fertilizers are almost always priced and sold by the 2,000-lb ton, but liquids and specialty blends sometimes come in different bag or tote sizes, and getting that number wrong throws off every downstream figure. Also remember this only compares nutrient cost — it doesn't account for application costs, timing, or nutrient-use efficiency differences between sources (for example, urea's volatilization risk versus UAN's runoff risk), which can matter as much as raw price per pound.
Product A: cost per lb nutrient ($)
$0.57
Product B: cost per lb nutrient ($)
$0.59
Inputs
Comparison
Cheaper product (1=A, 2=B)
1
Which product has the lower per-unit nutrient cost.
Savings (%)
4.8%
Percentage savings from choosing the cheaper product.
Product A: cost per acre ($)
$67.83
Cost to apply target nutrient rate with Product A.
Product B: cost per acre ($)
$71.25
Cost to apply target nutrient rate with Product B.
Product A: lbs/acre
260.9
Pounds of Product A needed per acre.
Product B: lbs/acre
375
Pounds of Product B needed per acre.
Product A: total field cost ($)
$6,782.61
Total cost for the whole field with Product A.
Product B: total field cost ($)
$7,125.00
Total cost for the whole field with Product B.
Savings per acre ($)
$3.42
Dollar savings per acre by choosing the cheaper product.
Total field savings ($)
$342.39
Total dollar savings for the whole field.
Product A: tons needed
13
Total tons of Product A for the field.
Product B: tons needed
18.8
Total tons of Product B for the field.
How to Use This Calculator
- Enter the price per ton and nutrient analysis (%) for Product A and Product B.
- Set the unit weight (lbs) for each product — typically 2,000 lbs (1 ton) for dry fertilizers.
- Enter Target Nutrient (lbs/acre) and Field Size (acres) for the season.
- Compare Cost per lb Nutrient for A and B — the lower cost-per-unit-of-nutrient is the better buy.
- Review Cost per Acre and Total Field Cost for both products to quantify your savings from the cheaper option.
How the result changes with Product A nutrient (%)
| Product A nutrient (%) | Product A: cost per lb nutrient ($) | Product B: cost per lb nutrient ($) |
|---|---|---|
| 23 | $1.13 | $0.59 |
| 35 | $0.74 | $0.59 |
| 69 | $0.38 | $0.59 |
| 100 | $0.26 | $0.59 |
What each input means
- Product A price ($/ton)
- Price per ton for Product A (e.g., urea at $520/ton).
- Product A nutrient (%)
- Nutrient analysis of Product A (e.g., urea = 46% N).
- Product A unit weight (lbs)
- Weight of one purchasing unit (bag, ton, etc.).
- Product B price ($/ton)
- Price per ton for Product B (e.g., UAN 32% at $380/ton).
- Product B nutrient (%)
- Nutrient analysis of Product B (e.g., UAN = 32% N).
- Product B unit weight (lbs)
- Weight of one purchasing unit.
- Target nutrient (lbs/acre)
- Desired pounds of nutrient per acre.
- Field size (acres)
- Total acres to fertilize.
What each result means
- Product A: cost per lb nutrient ($)
- Dollar cost per pound of actual nutrient from Product A.
- Product B: cost per lb nutrient ($)
- Dollar cost per pound of actual nutrient from Product B.
- Cheaper product (1=A, 2=B)
- Which product has the lower per-unit nutrient cost.
- Savings (%)
- Percentage savings from choosing the cheaper product.
- Product A: cost per acre ($)
- Cost to apply target nutrient rate with Product A.
- Product B: cost per acre ($)
- Cost to apply target nutrient rate with Product B.
- Product A: lbs/acre
- Pounds of Product A needed per acre.
- Product B: lbs/acre
- Pounds of Product B needed per acre.
- Product A: total field cost ($)
- Total cost for the whole field with Product A.
- Product B: total field cost ($)
- Total cost for the whole field with Product B.
- Savings per acre ($)
- Dollar savings per acre by choosing the cheaper product.
- Total field savings ($)
- Total dollar savings for the whole field.
- Product A: tons needed
- Total tons of Product A for the field.
- Product B: tons needed
- Total tons of Product B for the field.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersProduct A price ($/ton) = 520, Product A nutrient (%) = 46, Product A unit weight (lbs) = 2000, Product B price ($/ton) = 380 = 8 input(s) provided
- Calculate Product A: cost per lb nutrientProduct A: cost per lb nutrient = priceA / (bagWeightA * analysisA / 100)0.565 = $0.565
- Calculate Product B: cost per lb nutrientProduct B: cost per lb nutrient = priceB / (bagWeightB * analysisB / 100)0.594 = $0.594
- Calculate Cheaper productCheaper product1 = 1
- Calculate SavingsSavings = max(costPerAcreA, costPerAcreB) > 04.8 = 4.8%
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why can't I just compare the price per ton of two fertilizers?
Because price per ton ignores nutrient concentration. A $520/ton bag of 46% urea delivers 920 lbs of actual N per ton, while a $380/ton tank of 32% UAN delivers only 640 lbs of N per ton — so the cheaper ton isn't necessarily the cheaper nutrient. This calculator divides price by (unit weight × analysis% ÷ 100) for both products so you're comparing dollars per pound of actual nutrient, the number that actually drives your fertility budget.
Why does changing the unit weight input change my results so much?
Unit weight sets the denominator in the cost-per-pound-of-nutrient formula, so it has a direct, linear effect on every downstream number — cost per acre, total field cost, and total tonnage all scale off it. Dry granular products are almost always sold by the 2,000-lb ton, but liquids, totes, and specialty blends can use different unit sizes, and entering the wrong one will silently misstate every result even though the price and analysis% look correct.
Does the cost-per-acre comparison assume both products are applied at the same rate?
No — it holds the target nutrient rate constant instead, which is the fairer comparison. The calculator works out how many pounds of each product it takes to deliver your target lbs of nutrient per acre (which differs by product since analysis% differs), then prices out that quantity, so the cost-per-acre figures reflect equal nutrient delivery rather than equal product volume.
Why doesn't the calculator factor in application cost or nutrient-use efficiency?
It's deliberately scoped to nutrient cost alone — price per unit divided by nutrient content — because that's the one number that's directly comparable across any two products regardless of form. It doesn't account for things like urea's volatilization losses versus UAN's runoff risk, or differences in spreading versus spraying costs, so a product that wins on pure nutrient cost isn't automatically the better agronomic choice once those factors are considered.
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Manure Nutrient Value Calculator
N-P-K value from manure type and application rate.
FertilizerFertilizer Blend Calculator
Custom blend proportions for target N-P-K analysis.
Soil ScienceNutrient Balance Calculator
Calculate nitrogen, phosphorus, and potassium surplus or deficit by comparing fertilizer and manure inputs against crop removal rates.
Fertilizer4R Nutrient Stewardship Calculator
Right source, rate, time, and place optimization scoring.
LandscapingLawn Fertilizer Calculator
Calculate the amount of fertilizer needed based on lawn size, NPK ratio, and desired nitrogen application rate.
More in Agriculture & Farming.