Calculator · commodity
Commodity blending calculator
Calculates the attribute value of a two-lot blend, or the quantity of a second lot that reaches a target value.
Result
Enter values to see a result.
Formula & assumptions
Two-lot blend: weighted average attribute
formula v1.0.0 · calc v1 · reviewed 2026-07-16x_blend = (q_A × x_A + q_B × x_B) ÷ (q_A + q_B)
Applies to: Two lots of one commodity, for a total-mass-denominated attribute on a common basis.
Assumptions
- The attribute is weighted by TOTAL MASS and blends LINEARLY. This holds only for an attribute whose denominator is total mass — wet-basis moisture is the archetype, because both the water and the total mass simply add.
- Both lots use the same unit and the same basis.
Limitations
- LINEAR ATTRIBUTES ONLY. Test weight, falling number, and most functional and rheological properties do NOT blend linearly, and a weighted average of them is simply wrong rather than approximate.
- TOTAL-MASS WEIGHTING ONLY. An attribute denominated on dry matter (dry-basis moisture, or protein and oil reported on a dry-matter basis) is weighted by DRY MATTER, not by total mass, and this formula must not be applied to one directly.
- Mixing bases silently corrupts the result: a wet-basis and a dry-basis figure cannot be averaged together.
- Arithmetic on a homogeneous mix. It assumes the blend is actually homogeneous, which is a physical operation, not a calculation.
Scope
Not a grading, compliance, or contract determination. A blended average does not establish that a lot meets a grade, and blending to disguise a defect or evade a standard is a matter for the applicable standard and law, not for this tool.
Sources: Food and Agriculture Organization of the United Nations (FAO) (opens in a new tab), Agriculture and Horticulture Development Board (AHDB) (opens in a new tab)
Two-lot blend: quantity of lot B to reach a target
formula v1.0.0 · calc v1 · reviewed 2026-07-16q_B = q_A × (x_A − x_target) ÷ (x_target − x_B)
Applies to: Two lots of one commodity, for a total-mass-denominated attribute on a common basis.
Assumptions
- The attribute is weighted by TOTAL MASS and blends linearly; both lots share a unit and basis.
- The target lies between the two lot values — a blend cannot leave the range its inputs span.
Limitations
- A target outside the range spanned by the two lots is unreachable by blending them, at any ratio. The formula rejects it rather than returning a negative quantity.
- LINEAR ATTRIBUTES ONLY. Test weight, falling number, and most functional and rheological properties do NOT blend linearly, so solving for a target value of one of them is wrong rather than approximate.
- Mixing bases silently corrupts the result: a wet-basis and a dry-basis figure cannot be blended together.
Scope
Not a grading, compliance, or contract determination, and not a route to meeting a specification a lot does not meet.
Sources: Food and Agriculture Organization of the United Nations (FAO) (opens in a new tab), Agriculture and Horticulture Development Board (AHDB) (opens in a new tab)
Moisture: dry basis → wet basis
formula v1.0.0 · calc v1 · reviewed 2026-07-16M_wb = M_db ÷ (100 + M_db) × 100
Applies to: Any commodity whose moisture is reported on a stated basis.
Assumptions
- Water and dry matter are the only components; nothing else is present or is being tracked.
Limitations
- A conversion between two denominators, not a measurement.
- The result approaches but never reaches 100%, which is the definitional ceiling of wet basis.
Scope
Arithmetic on the numbers entered. It does not replace representative sampling or a calibrated, correctly-referenced moisture meter, and it cannot detect that an input was wrong.
Sources: Food and Agriculture Organization of the United Nations (FAO) (opens in a new tab), USDA Agricultural Research Service (ARS) (opens in a new tab)
Moisture: wet basis → dry basis
formula v1.0.0 · calc v1 · reviewed 2026-07-16M_db = M_wb ÷ (100 − M_wb) × 100
Applies to: Any commodity whose moisture is reported on a stated basis.
Assumptions
- Water and dry matter are the only components; nothing else is present or is being tracked.
Limitations
- A conversion between two denominators. It does not tell you which basis your own figure used — that must come from the method or contract that produced it.
- Dry basis has no upper bound: a lot with more water than solids exceeds 100% dry basis, which is arithmetically correct rather than an error.
Scope
Arithmetic on the numbers entered. It does not replace representative sampling or a calibrated, correctly-referenced moisture meter, and it cannot detect that an input was wrong.
Sources: Food and Agriculture Organization of the United Nations (FAO) (opens in a new tab), USDA Agricultural Research Service (ARS) (opens in a new tab)
About this tool
- Linear attributes only. Test weight, falling number, and most functional and rheological properties do not blend linearly, and a weighted average of them is wrong rather than approximate — this tool refuses them rather than returning a plausible-looking figure.
- Both lots must share a unit and a basis. Mixing bases silently corrupts the result, which is why the basis is an explicit input carried through to the output.
- Arithmetic on a homogeneous mix. Whether the blend is actually homogeneous is a physical operation, not a calculation.
- Two lots only.
Educational reference — not a prescription
Not a grade, compliance, or contract determination. A blended average does not establish that a lot meets a grade or a specification, and blending to disguise a defect or evade a standard is a matter for the applicable standard and the law, not for this tool.
- These calculators are for education and reference. The quality of any result depends entirely on the accuracy of the values you enter.
- Local agronomic conditions, legal requirements, product labels, and professional advice may override a general calculation.
- Results are not pesticide, fertilizer, irrigation, or veterinary prescriptions, and are not a substitute for advice from a qualified agronomist or your local extension service.