Enter the cow body weight and the diet Neutral Detergent Fiber (NDF, % of dry matter) into the Dry Matter Intake Calculator. The calculator will estimate the Dry Matter Intake (DMI) per day.

Dry Matter Intake Calculator

Enter any 2 values to calculate the missing variable


Related Calculators

Dry Matter Intake Formula

The following example problem outlines the steps and information needed to calculate the Dry Matter Intake (DMI) using a common forage-based rule of thumb.

DMI = CBW * 1.2 / NDF

Variables:

  • DMI is the Dry Matter Intake (lb/day)
  • CBW is the cow body weight (lb)
  • NDF is the Neutral Detergent Fiber content of the diet (% of dry matter, entered as a percent such as 50)

To estimate the dry matter intake, multiply the cow body weight by 1.2, then divide by NDF (%). (This comes from DMI as a percent of body weight ≈ 120 / NDF(%).)

How to Calculate Dry Matter Intake?

The following steps outline how to calculate the Dry Matter Intake.


  1. First, determine the cow body weight (lb).
  2. Next, determine the diet NDF (% of dry matter).
  3. Next, gather the formula from above: DMI = CBW * 1.2 / NDF.
  4. Finally, calculate the Dry Matter Intake (lb/day or kg/day).
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

cow body weight (lb) = 1300

NDF (% of dry matter) = 50

DMI = CBW * 1.2 / NDF = ?

Answer: DMI = 1300 × 1.2 / 50 = 31.2 lb/day