Reference formulas and worked examples below keep their stated units. Monetary examples use USD; dimensional examples use US customary units unless labeled otherwise. Metric calculator inputs are converted to these reference units before calculation. Choosing another currency does not convert example amounts or exchange money.
How to use this tdee calculator
Enter height, weight and age. Choose an equation coefficient and an activity multiplier; compare the scenarios below.
How the calculation works
Estimate resting kcal/day with the Mifflin–St Jeor equation: 10 × kg + 6.25 × cm − 5 × age, then add +5 or −161.
Estimated TDEE = resting estimate × selected activity factor. A 1.5 factor means modeled total use is 50% above the resting estimate. The preset factors are scenarios, not a conversion from workout frequency.
The method uses the energy-to-resting-energy ratio described in the NIDDK model; it does not reproduce that model’s dynamic weight-change simulation. Scenario values are rounded for display.
Worked example
With an estimated resting use of 1,648.75 kcal/day and a 1.5 activity factor, modeled daily use is 2,473.13 kcal (shown as 2,473). At 1.85, the same resting estimate gives 3,050.19 kcal/day. The difference comes from the activity assumption.
Limits and assumptions
An estimate from adult measurements, not a measured metabolic rate or a diagnosis. This model does not adjust for pregnancy, breastfeeding, illness, unusual body composition or athletic training. The source equation studied adults aged 19–78; this tool keeps that age range. It is not a calorie restriction or weight-loss prescription. Constant activity and current measurements only; it does not forecast body-weight change or prescribe a calorie deficit.
Frequently asked questions
Why might another TDEE calculator differ?
Calculators can use different resting equations and activity multipliers. Compare those assumptions before comparing the totals.
Are the presets exact activity measurements?
No. They represent broad scenarios. Work, walking, training and individual physiology can change actual energy use.
Can I enter a 1.2 multiplier?
Yes. Choose a custom multiplier and enter 1.2. The tool supports explicit factors from 1 to 3.
Does TDEE predict how quickly I will lose weight?
No. This tool estimates energy use under a fixed scenario. Weight change over time requires a different model and assumptions.
References
Mifflin et al.: predicting resting energy expenditure (1990)