Enter sample weights, dry matter, or moisture to calculate dry matter percentage and optionally find dry matter and water in an as-fed amount.
Advanced options
Amount conversion
Nutrient conversion
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Table of contents
How to use our Dry Matter Calculator
- Choose the type of information you have: wet and dry weights, a reported dry matter percentage, or a reported moisture percentage.
- For measured weights, select the scale unit and enter the wet and dry weights from the same sample. For moisture, select wet basis or dry basis exactly as the report states it.
- Open Advanced options only if you want to convert an as-fed amount, convert a nutrient from an as-fed basis, or change the displayed decimal places.
- Click Calculate. Check that dry matter percentage is from 0% through 100%, and, when you entered an as-fed amount, that dry matter amount plus water amount equals that amount.
Definitions
Dry matter: The part of a wet or as-fed sample that remains after water is excluded.
Dry matter percentage: Dry matter as a percentage of the total wet or as-fed mass.
As-fed: A weight or nutrient percentage measured in the material as supplied, including its water.
Wet-basis moisture: Water mass divided by total wet mass, expressed as a percentage. [1]
Dry-basis moisture: Water mass divided by dry mass, expressed as a percentage. It can be greater than 100%.
Dry-matter basis: A nutrient percentage expressed as a share of dry matter, used to compare materials with different water amounts.
Common mistakes and quick fixes
Mistake: Using wet and dry weights from different samples, batches, or scale units.
Fix: Use the same sample before and after drying, with the same unit for both readings.
Mistake: Entering a dry weight greater than the wet weight.
Fix: Recheck the readings and labels. Dry weight cannot exceed the starting wet weight for the same sample.
Mistake: Treating wet-basis and dry-basis moisture as the same percentage.
Fix: Copy the basis named by the report. Wet-basis moisture uses total wet mass, while dry-basis moisture uses dry mass.
Mistake: Comparing an as-fed nutrient percentage directly with a dry-matter-basis percentage.
Fix: Convert the as-fed nutrient percentage to a dry-matter basis before comparing materials with different moisture levels.
Mistake: Entering a nutrient percentage greater than total dry matter percentage.
Fix: Check the nutrient basis and decimal point. A nutrient that is part of dry matter cannot exceed the dry matter percentage.
Limitations & Key Assumptions / Boundary Conditions
- Measured-weight results assume the wet and dry readings are from the same sample and that drying removed water without losing other material.
- A reported dry matter or moisture value is used as entered. The calculator does not determine whether it matches the current batch, forage, feed, food, or material.
- Wet-basis moisture must be from 0% through 100%. Dry-basis moisture can exceed 100% because its denominator is dry mass.
- Nutrient conversion applies only when the entered nutrient is reported on an as-fed basis and is part of the dry matter.
- Dry matter percentage describes water content. It does not measure nutrient quality, safety, digestibility, or usable feed value.
Methodology
Dry matter percentage
For measured weights, dry matter percentage is the dried mass divided by the starting wet mass. Both readings must use the same mass unit, so the unit cancels in the ratio.
Dry matter (%) = (dry sample weight / wet sample weight) x 100
If you enter a known dry matter percentage, the calculator uses that reported value directly.
Dry matter (%) = reported dry matter (%)
For wet-basis moisture, water is measured against the full wet mass, so dry matter is the percentage left after moisture is subtracted. [1]
Dry matter (%) = 100 - wet-basis moisture (%)
For dry-basis moisture, water is measured against dry mass, so a different denominator is required.
Dry matter (%) = 10000 / (100 + dry-basis moisture (%))
Optional conversions
For an entered as-fed amount, the calculator separates total mass into dry matter and water. For an as-fed nutrient percentage, it divides by the dry matter share to express that nutrient on a dry-matter basis. Nutrient conversion is unavailable at 0% dry matter because division by zero is undefined.
Dry matter amount = as-fed amount x dry matter (%) / 100
Water amount = as-fed amount - dry matter amount
Nutrient on dry-matter basis (%) = as-fed nutrient (%) / (dry matter (%) / 100)
Worked example
A sample weighs 500 g before drying and 175 g after drying. Dry matter is (175 / 500) x 100 = 35%. If 25 lb of the same material is as-fed, it contains 8.75 lb of dry matter and 16.25 lb of water.