Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Fertilizer value per ton
$12.35
Total value applied
$6,175
Nitrogen value per ton
$3.30
Phosphate value per ton
$4.55
Potash value per ton
$4.50
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How to use this
- 1Enter total nitrogen (lb/ton).
- 2Enter first-year n availability (%).
- 3Enter p2o5 (lb/ton).
- 4Enter k2o (lb/ton).
- 5Enter nitrogen price ($/lb).
- 6Enter p2o5 price ($/lb).
- 7Enter k2o price ($/lb).
- 8Enter tons applied.
- 9Read your fertilizer value per ton on the right — it updates as you type.
- 10Hit Share to keep the scenario or send it to someone.
About this calculator
Manure is a fertilizer source that farms often undervalue because the nutrient content isn't printed on a bag. This calculator takes manure analysis results (or typical book values by species) in lb of N, P2O5, and K2O per ton, applies a nitrogen availability factor since not all manure N is plant-available in year one, and prices the result against current commercial fertilizer prices to show what a load of manure is actually worth as a fertilizer replacement. This is the number to use when deciding whether hauling manure further to a needier field pencils out, or when negotiating price for manure being sold off a livestock operation.
Worked example
Using the values the calculator loads with:
Inputs
- Total nitrogen: 11 lb/ton
- First-year N availability: 50 %
- P2O5: 7 lb/ton
- K2O: 9 lb/ton
- Nitrogen price: 0.6 $/lb
- P2O5 price: 0.65 $/lb
- K2O price: 0.5 $/lb
- Tons applied: 500
Results
- Fertilizer value per ton: $12.35
- Total value applied: $6,175
- Nitrogen value per ton: $3.30
- Phosphate value per ton: $4.55
- Potash value per ton: $4.50
What each field means
Inputs
- Total nitrogen (lb/ton)
- The total nitrogen used in the calculation, measured in lb/ton. Starts at 11 lb/ton so you have a working example on load.
- First-year N availability (%)
- The first-year n availability used in the calculation, measured in %. Starts at 50 % so you have a working example on load. Accepted range: 10–100 %.
- P2O5 (lb/ton)
- The p2o5 used in the calculation, measured in lb/ton. Starts at 7 lb/ton so you have a working example on load.
- K2O (lb/ton)
- The k2o used in the calculation, measured in lb/ton. Starts at 9 lb/ton so you have a working example on load.
- Nitrogen price ($/lb)
- The nitrogen price used in the calculation, measured in $/lb. Starts at 0.6 $/lb so you have a working example on load.
- P2O5 price ($/lb)
- The p2o5 price used in the calculation, measured in $/lb. Starts at 0.65 $/lb so you have a working example on load.
- K2O price ($/lb)
- The k2o price used in the calculation, measured in $/lb. Starts at 0.5 $/lb so you have a working example on load.
- Tons applied
- The tons applied used in the calculation. Starts at 500 so you have a working example on load.
Results
- Fertilizer value per ton
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total value applied
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Nitrogen value per ton
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Phosphate value per ton
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Potash value per ton
- 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 isn't all the nitrogen in manure counted at full value?
A large share of manure nitrogen is organic and mineralizes slowly over 2-3 years rather than being immediately plant-available like urea. First-year availability runs roughly 35-50% for solid manure and can be higher, 50-70%, for liquid/slurry manure incorporated quickly, with the remainder crediting future crop years.
Should I get my manure tested instead of using book values?
Yes, always test if you're applying regularly — nutrient content in manure varies 2-3x depending on bedding type, storage method, and dilution, and book values are only a rough starting point. A $20-30 lab test easily pays for itself in more accurate fertilizer planning.
Does this account for hauling and application cost?
No, this is gross nutrient value only. Subtract your actual hauling and spreading cost per ton, commonly $4-10/ton depending on distance and equipment, to get the net value of applying manure versus buying commercial fertilizer instead.
How do I value manure I'm selling versus applying myself?
Use the same nutrient value as your floor price, then negotiate based on who pays hauling. Buyers close to the source should expect to pay closer to full nutrient value since they save the seller a disposal cost, while distant buyers factor in trucking against that ceiling.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Manure Nutrient Value Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/manure-nutrient-value
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/manure-nutrient-value" target="_blank" rel="noopener">Manure Nutrient Value Calculator — RevenueLab</a> (2026).</p>
Source: [Manure Nutrient Value Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/manure-nutrient-value) (2026).