TDEE Calculator
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What Your Result Means
- TDEE: Your estimated total daily energy expenditure — the number of calories you burn in a full day including all activity. Eating at this level generally maintains your current weight.
- BMR (resting): Your basal metabolic rate — calories burned just to keep your body alive at complete rest. This is typically 60–75% of your total daily burn.
- Activity levels: The five rows show how your TDEE changes across different exercise frequencies, so you can see the impact of training more or less.
- Weight goals: To lose weight, eat roughly 300–500 calories below your TDEE. To gain, eat 250–500 above. Consult a dietitian for personalized guidance.
How This Calculator Works
You enter your age, sex, height, weight, and activity level. The tool converts your measurements to metric, then applies the Mifflin-St Jeor equation to estimate BMR. It multiplies BMR by a standard activity factor (1.2 for sedentary through 1.9 for extremely active) to produce your TDEE. The formula assumes typical body composition and does not account for unusually high or low muscle mass.
Quick Questions
What activity level should I pick?
Be honest about your typical week, not your best week. "Moderately active" fits most people who exercise 3–5 days. If your job involves sitting all day and you only train 1–2 times a week, "lightly active" is more accurate.
Is Mifflin-St Jeor better than Harris-Benedict?
Research generally shows Mifflin-St Jeor is more accurate for most adults, especially people of healthy weight. Harris-Benedict tends to overestimate by about 5%. Both are estimates — real-world needs vary.
How do I use TDEE for weight loss?
A deficit of 300–500 calories per day below your TDEE typically yields about 0.5–1 lb of fat loss per week. Aggressive deficits (over 1,000 cal) risk muscle loss, fatigue, and nutrient gaps. Consult a healthcare provider before starting a restrictive diet.
Why does the result change so much with activity level?
Activity multipliers range from 1.2 to 1.9, so an extremely active person burns roughly 60% more than a sedentary person with the same body stats. Even one step up in activity adds 200–400 calories per day for most people.
Does this account for muscle mass?
No. Mifflin-St Jeor uses total body weight, not lean mass. Very muscular individuals may have a higher actual BMR than the estimate, while people with above-average body fat may have a lower one.
Sources
- Mifflin et al. (1990) — A new predictive equation for resting energy expenditure (original Mifflin-St Jeor research)
- National Academies — Dietary Reference Intakes for Energy (activity factor definitions)
- CDC — Balancing Calories (calorie balance and weight management overview)
Method & review
Estimate only. Results reflect your inputs and standard formulas — they are not financial, tax, legal, health, or investment advice. Verify important decisions with a qualified professional.