Calculate RDI calories: estimate your daily maintenance calories in kcal or kJ from age, sex, weight, height and activity, or for a weight goal.
RDI Calories Formula
Your daily calorie result is built in two steps: calculate resting calories from body size, age, and sex, then apply an activity multiplier.
- W = weight in kilograms
- H = height in centimeters
- A = age in years
Assumed Activity Multipliers
These conventional multipliers are scaling assumptions, not factors validated by the original resting-energy equation. The equation was derived in healthy adults ages 19–78; retained ages 18 and 79–100 extrapolate beyond that study. This tool is not for pregnancy, breastfeeding or individualized clinical nutrition.
| Activity Level | Multiplier | Typical Routine |
|---|---|---|
| Sedentary | 1.20 | Little exercise and mostly sitting |
| Lightly Active | 1.375 | Light exercise 1 to 3 days per week |
| Moderately Active | 1.55 | Moderate exercise 3 to 5 days per week |
| Very Active | 1.725 | Hard exercise 6 to 7 days per week |
| Extra Active | 1.90 | Very hard training or a physically demanding job |
How to Use the Calculator
- Select a solve task, your weight unit, and centimeters or feet and inches for height. Changing units or height entry converts your current measurements.
- Enter your age, sex, weight, and height.
- Choose the activity level that best matches your average week.
- For the weekly-change scenario, enter a signed change: negative for loss, positive for gain. Select Calculate to see the estimate or illustrative energy scenario.
Example Calculation
A 30-year-old male who weighs 70 kg, is 175 cm tall, and is moderately active would calculate daily calories like this:
That gives a maintenance intake of 2,556 calories per day.
Illustrative Static Energy Adjustments
The arithmetic examples below show adjustments to estimated maintenance energy. They are not calorie prescriptions or weight-change predictions. The calculator’s weekly-change scenario uses maintenance + weekly kilograms × 7,700 ÷ 7; real energy expenditure and body-weight responses change over time:
What Changes Daily Calorie Needs
- Body weight: heavier bodies generally require more calories.
- Height: taller people usually burn more calories at rest.
- Age: calorie needs often decline gradually with age.
- Sex: the formula applies a different resting-calorie constant for men and women.
- Activity: the biggest day-to-day driver beyond body size is movement and training volume.
FAQ
What does RDI mean here?
Here, RDI calories refers to an estimated maintenance-energy value, not a nutrient Reference Daily Intake or a measured personal requirement.
Is this for maintenance or fat loss?
Choose estimated maintenance energy or an illustrative signed weekly-change energy scenario. The fixed 7,700 kcal/kg scenario cannot reliably predict a weekly weight trend and is not an intake recommendation.
When should I recalculate?
Recalculate after a meaningful change in body weight, training frequency, or daily activity level.
