Enter the body weight into the calculator to determine the Resting Energy Requirement. This calculator can also evaluate any of the variables given the others are known.

Rer (Resting Energy Requirement) Formula

The following formula is used to calculate the Resting Energy Requirement (RER).

RER = 70 * (BW^{0.75})

Variables:

  • RER is the Resting Energy Requirement (kcal/day)
  • BW is the body weight in kilograms (kg)

To calculate the Resting Energy Requirement, raise the body weight to the power of 0.75. Then, multiply the result by 70. This will give you the Resting Energy Requirement in kilocalories per day.

What is a Rer (Resting Energy Requirement)?

The Resting Energy Requirement (RER) is the amount of energy or calories that an individual’s body needs to perform basic, at-rest functions such as breathing, circulating blood, and regulating body temperature. It is essentially the minimum amount of energy required to keep the body functioning while at rest. This does not include the energy needed for physical activity or digestion. RER is often used as a baseline when determining an individual’s total daily energy needs.

How to Calculate Rer (Resting Energy Requirement)?

The following steps outline how to calculate the Resting Energy Requirement (RER).


  1. First, determine the body weight in kilograms (BW).
  2. Next, raise the body weight to the power of 0.75.
  3. Next, multiply the result by 70.
  4. Finally, calculate the Resting Energy Requirement (RER).
  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.

Body weight (BW) = 10 kg