Compare two fertilizer quotes by nutrient targets, product rate, material cost, and optional delivery or spreading charges per acre.
Quote A
Quote B
Advanced options
Field size
Quote A charges
Quote B charges
Table of contents
How to use our Fertilizer Blend Cost Comparison Calculator
- Enter the planned Nitrogen target, Phosphate target, and Potash target in pounds per acre. Enter 0 for a nutrient you do not need.
- For each quote, copy the product name, printed N-P2O5-K2O grade, quoted price, and the exact price basis. Enter bag weight only when the quote is priced per bag.
- Select Advanced options only if you need field totals or want to include delivery, per-ton, or spreading charges.
- Click Calculate and first check the target-fit recommendation. A lower-priced product is not recommended if it misses any positive nutrient target.
- Sanity-check the calculated product rate and delivered nutrients against the printed grade. If a rate is 500 lb product per acre for a 10-10-10 product, it should deliver 50 lb of each listed nutrient per acre.
Definitions
Fertilizer grade (N-P2O5-K2O): The three percentages printed on a fertilizer label. For example, 18-46-0 is 18% nitrogen, 46% phosphate as P2O5, and 0% potash as K2O by product weight.
Nitrogen, phosphate, and potash targets: The planned pounds of N, P2O5, and K2O per acre. These are nutrient amounts, not pounds of fertilizer product.
Product rate: Pounds of fertilizer product needed per acre to meet the highest requirement among the positive nutrient targets that the product contains.
Material cost per pound of nutrient: The fertilizer-only price assigned to one pound of N, P2O5, or K2O. It excludes delivery and spreading charges.
Shortfall: The amount of a target nutrient that the calculated product rate does not supply. A shortfall of 0 means that nutrient target is met or exceeded.
US short ton: A weight of 2,000 lb, used for many bulk fertilizer quotes.
All-in cost per acre: Material cost plus any entered per-short-ton surcharge, per-acre spreading charge, and fixed delivery fee divided by field area.
Common mistakes and quick fixes
Mistake: Entering only two numbers in Quote A fertilizer grade, such as 18-46.
Fix: Enter all three label numbers in N-P2O5-K2O order, such as 18-46-0.
Mistake: Using elemental phosphorus or potassium in the Phosphate target or Potash target.
Fix: Copy recommendations stated as lb P2O5/acre and lb K2O/acre, which match the fertilizer grade label.
Mistake: Selecting the wrong unit in Quote A price is for.
Fix: Match the supplier quote exactly. A US short ton price is divided by 2,000, while a per-pound price is already a price per pound.
Mistake: Choosing one bag in Quote B price is for but leaving Quote B bag weight blank or entering the number of bags.
Fix: Enter the net weight of one bag in pounds, such as 50.
Mistake: Entering a fixed charge in Quote A fixed delivery fee ($ per order) without entering Field area (acres).
Fix: Enter the treated acres so the fixed fee can be divided across the field.
Mistake: Treating the lowest Quote A material cost per acre as an automatic winner.
Fix: Read Target-fit recommendation first, then compare all-in costs only among quotes that meet every positive target.
Limitations & Key Assumptions / Boundary Conditions
- This compares each quote as one fertilizer product. It does not build a custom blend from two or more products.
- A quote qualifies only when its calculated rate meets every positive N, P2O5, and K2O target. It can still supply more of another nutrient than planned.
- Results use the guaranteed analysis entered in the fertilizer grade. They do not adjust for application losses, placement, soil chemistry, timing, nutrient availability, or crop response.
- Fixed delivery fees are included per acre only when a positive Field area (acres) is entered. Blank optional charges count as $0.
- Prices are compared using a US short ton of 2,000 lb. Enter a bag price only with the net weight of one bag.
- Use a soil test, nutrient plan, and local application guidance to choose nutrient targets. This calculator compares quote arithmetic, not agronomic suitability.
Methodology
How the quote comparison works
The calculator reads each fertilizer grade as N-P2O5-K2O percentages. It changes the quote price into dollars per pound of product, then calculates the product rate needed for each nutrient target. The largest required rate becomes the calculated product rate because that rate supplies every nutrient the product contains.
price per lb = price per short ton / 2,000
nutrient-driven rate = nutrient target / nutrient fraction
product rate = highest nutrient-driven rate
nutrient delivered = product rate * grade percentage * 0.01
A positive target paired with a 0% nutrient in the grade makes that quote incomplete. The calculator shows the shortfall and does not recommend that quote as a complete single-product choice. Nutrient shortfall is limited to zero when the product supplies extra nutrient because this output measures only what is missing.
shortfall = max(0, target - nutrient delivered)
material cost per acre = product rate * price per lb
Optional charges are added after the material-only calculation. A per-short-ton charge scales with the calculated product rate, a spreading charge is added per acre, and a fixed delivery fee is divided by entered field acres.
all-in cost per acre = material cost + surcharge per ton * product rate / 2,000 + spreading per acre + delivery fee / field area
all-in cost difference per acre = Quote B all-in cost - Quote A all-in cost
Worked example
Suppose the targets are 50 lb N/acre and 40 lb P2O5/acre, and a quote is 18-46-0 at $700 per US short ton. Its price is $0.35 per lb of product. Meeting 50 lb N needs 50 / 0.18 = 277.78 lb product/acre, which delivers 127.78 lb P2O5/acre. The material cost is 277.78 * $0.35 = $97.22 per acre before optional charges. The calculator compares that all-in cost only with other quotes that also meet all positive targets.
What this calculation leaves out
The calculation assumes the entered price, grade, field area, and charges are correct. It treats each nutrient target as a minimum and does not assign a penalty or value to extra nutrient. It also does not estimate the cost of adding another fertilizer to correct a shortfall. A US short ton is converted as 2,000 lb.