- Estimated maintenance energy
- 1,648.75 kcal/day
- Estimated resting energy
- 1,648.75 kcal/day
- Maintenance energy in kilojoules
- 6,898.37 kJ/day
How it works
Factor one is the resting baseline
An activity factor of 1 leaves the resting estimate unchanged. Before treating the result as a typical day’s total expenditure, check whether you intentionally chose that baseline or meant to model additional daily activity.
How activity assumptions affect TDEE
An estimated resting expenditure of 1,600 kcal/day becomes 1,920 with an activity factor of 1.2, or 2,480 with a factor of 1.55. That 560 kcal/day difference comes entirely from the activity assumption, not a new measurement of metabolism. When comparing results, keep body measurements and the resting-energy equation unchanged so you can see that effect. The activity-adjusted total already includes modeled activity; adding a separate exercise estimate may count part of that expenditure twice. This is a scenario estimate, not a personalized intake prescription.
Daily energy: formula and assumptions
Mifflin–St Jeor: BMR = 10w + 6.25h − 5a + s; s = 5 for male and −161 for female. TDEE = BMR × activity factor.
Weight is in kilograms, height in centimeters, and age in years. This is a population estimate, not a measured metabolic rate.
Food energy conversion: formula and assumptions
1 kilocalorie = 4.184 kilojoules.
A food Calorie with a capital C is one kilocalorie.
Calories, kilocalories & joules: formula and assumptions
1 thermochemical cal = 4.184 J; 1 food Calorie = 1 kcal = 1,000 cal.
Capital-C dietary Calories represent kilocalories. The converter keeps small calories, food Calories and joules clearly distinguished.
Worked example
Using the Daily energy example:
- Sex used by the equation
- Male
- Age (years)
- 30
- Measurement system
- Metric (kg, cm)
- Weight (kg)
- 70
- Height (cm)
- 175
- Energy equation
- Mifflin–St Jeor
- Activity level
- Resting energy only
Mifflin–St Jeor: BMR = 10w + 6.25h − 5a + s; s = 5 for male and −161 for female. TDEE = BMR × activity factor.
Example result
Estimated maintenance energy: 1,648.75 kcal/day
Estimated resting energy: 1,648.75 kcal/day
Maintenance energy in kilojoules: 6,898.37 kJ/day
These are illustrative inputs. Change the values to explore a different scenario.
What to keep in mind
Adult estimates do not apply to pregnancy, breastfeeding, growing children, or individualized medical nutrition care.
Formula references
- Mifflin et al.: resting energy expenditure (opens in a new tab)
- NIST SP 811 Appendix B.8 conversion factors (opens in a new tab)
References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.
Common questions
Why does changing activity level change TDEE?
TDEE multiplies the estimated resting expenditure by an activity factor. The result therefore depends on that activity assumption.
Does TDEE stay constant every day?
Not necessarily. This model gives a single scenario estimate; actual activity, health and other circumstances can change daily expenditure.
Prepared by Finflo. See our methodology and editorial policy. Read the relevant professional-advice limitations.