TDEE & Calorie Calculator

The calculation begins with your Basal Metabolic Rate (BMR), the energy required to keep vital organs functioning while you are at complete rest. Research published in nutrition journals consistently ranks the Mifflin-St Jeor equation among the most reliable BMR estimates for healthy adults, outperforming older formulas such as Harris-Benedict in validation studies.

For men, BMR equals (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5. For women, the same formula applies but subtracts 161 instead of adding 5. These sex-specific constants reflect average differences in lean tissue and hormonal influences on resting metabolism.

Your BMR is then multiplied by an activity factor that ranges from 1.2 for sedentary lifestyles to 1.9 for people with physically demanding jobs plus regular training. The product is your TDEE, or maintenance calories. For weight goals, we adjust TDEE by roughly 275 to 1,100 calories per day. A daily deficit or surplus of about 550 calories typically corresponds to a change of 0.5 kg per week, though individual results vary.

• Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
• Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
• TDEE = BMR × activity factor (1.2 to 1.9)

Your TDEE represents the calorie intake that should keep your weight roughly stable, assuming your activity level stays consistent. If you eat below this number consistently, you create a deficit that encourages fat loss over time. Eating above it supports weight gain, which can include muscle when combined with resistance training and adequate protein.

Compare your recommended goal calories to your current average intake. A gap of 300 to 500 calories below maintenance is a sustainable starting point for fat loss. Aggressive deficits above 750 calories may produce faster scale changes but often increase hunger, fatigue, and muscle loss. Gradual adjustments tend to produce more lasting results.

Track your weight for two to three weeks at your target intake. If the scale is not moving in the direction you expect, adjust calories by 100 to 150 per day rather than making large swings. Remember that water retention, menstrual cycles, and sodium intake can mask fat loss on the scale for several days at a time.

Once you have a calorie target that works, the next step is dividing those calories into protein, carbohydrates, and fat. Your TDEE is the anchor number; macro distribution fine-tunes how those calories support performance, recovery, and body composition.

All BMR equations, including Mifflin-St Jeor, predict averages for a given age, sex, height, and weight. They cannot account for individual differences in muscle mass, genetics, thyroid function, or metabolic adaptation after prolonged dieting. Athletes and people with unusually high lean mass may need more calories than the formula suggests.

Activity multipliers are broad categories, not precise measurements. Two people who both train five days per week may burn very different amounts of energy depending on workout intensity, non-exercise movement, and job type. Treat your TDEE as an educated starting estimate, not a fixed prescription.