Dry Matter Calculator

What Is Dry Matter?

Dry matter (DM) is the portion of feed that remains after all water is removed.

Every feed ingredient contains:

• Water (moisture)
• Nutrients (protein, fiber, fat, minerals, energy)

Animals receive nutrients from the dry portion, not the water. Water adds weight but does not add nutritional value.

For example:

• Fresh silage may contain 65% moisture
• That means it only contains 35% dry matter
• You are paying for 65% water if you buy it “as-fed”

That is why dry matter analysis is critical.

Why Dry Matter Percentage Matters

1. Accurate Feed Comparison

Two feeds may look similar in price per ton, but moisture content can change the real cost dramatically.

Example:

• Feed A: $60 per ton at 30% DM
• Feed B: $90 per ton at 90% DM

Feed A appears cheaper. But when adjusted to dry matter, it may actually cost more per ton of nutrients.

2. Proper Ration Formulation

Livestock nutrition programs are built on dry matter intake (DMI), not as-fed weight.

If you do not calculate DM correctly:

• Cattle may be underfed or overfed
• Milk production can drop
• Feed efficiency declines
• Health problems may increase

3. True Cost Evaluation

Moisture-heavy feeds often appear cheaper on paper. A dry matter calculator reveals the real price per ton of nutrients.

How the Dry Matter Calculator Works

This calculator uses the gravimetric method, which is the standard laboratory technique for moisture analysis.

It requires three measurements:

1. Container Weight (Tare) – Empty dish weight
2. Container + Wet Sample – Before drying
3. Container + Dry Sample – After oven drying

Optional:
4. Price per Ton (As-Fed) – For cost analysis

Dry Matter Formula

The calculator uses this formula:

Step 1: Calculate Wet Sample Weight

Wet Sample = (Container + Wet Sample) − Tare

Step 2: Calculate Dry Sample Weight

Dry Sample = (Container + Dry Sample) − Tare

Step 3: Calculate Dry Matter Percentage

[
Dry Matter (%) = \left(\frac{Dry Sample}{Wet Sample}\right) \times 100
]

Step 4: Calculate Moisture Percentage

[
Moisture (%) = 100 – Dry Matter (%)
]

Step 5: Calculate True Cost on Dry Matter Basis

Where:

Practical Example

Let’s walk through a real-world scenario.

Measurements:

• Tare (empty dish): 120 g
• Container + Wet Sample: 420 g
• Container + Dry Sample: 300 g
• Price: $70 per ton (as-fed)

Step 1: Wet Sample Weight

420 − 120 = 300 g

Step 2: Dry Sample Weight

300 − 120 = 180 g

Step 3: Dry Matter %

(180 ÷ 300) × 100 = 60%

Step 4: Moisture %

100 − 60 = 40%

Step 5: True Cost (DM Basis)

DM Ratio = 0.60

$70 ÷ 0.60 = $116.67 per ton (dry matter basis)

Even though the feed costs $70 per ton as-fed, you are effectively paying $116.67 per ton for actual nutrients.

That is a big difference.

Understanding the Calculator Inputs

Here is what each field means:

Container Weight (Tare) [g]

The weight of the empty drying dish. This ensures accuracy by isolating the sample weight.

Container + Wet Sample [g]

The total weight before drying.

Container + Dry Sample [g]

The total weight after drying removes moisture.

Price per Ton (Optional)

If entered, the calculator shows:

• Cost As-Fed
• True Cost (Dry Matter Basis)

If no price is entered, it only calculates composition.

Common Errors to Avoid

The calculator includes safeguards to prevent mistakes:

• Tare weight cannot be heavier than sample weights
• Dry weight cannot exceed wet weight
• All three weights must be entered

To improve accuracy:

• Use a calibrated scale
• Dry samples completely
• Avoid contamination or material loss

When Should You Use a Dry Matter Calculator?

This tool is especially useful for:

• Dairy farmers
• Beef producers
• Feedlot operators
• Nutritionists
• Agricultural researchers
• Feed buyers comparing suppliers

It is most important when working with:

• Silage
• Haylage
• High-moisture corn
• Wet distillers grains
• Any feed above 15% moisture

Dry Matter vs As-Fed: Key Difference

Always compare feeds on a dry matter basis for fair evaluation.

Benefits of Using This Dry Matter Calculator

• Fast and accurate calculation
• Standard gravimetric method
• Automatic moisture percentage
• Instant cost conversion
• Simple input fields
• Clear validation checks

It removes guesswork and shows the real numbers behind feed value.