Calculate your BMR and TDEE using the Mifflin-St Jeor equation. Enter your age, weight, height, and activity level to see your daily calorie target for weight loss, maintenance, or muscle gain. Add body fat percentage for calculations based on lean body mass.
Disclaimer: This calculator provides estimates based on standard formulas. Consult a healthcare provider before making significant dietary changes, especially if you have medical conditions.
Last updated: January 15, 2025
| Goal | Daily Calories | Weekly Change |
|---|---|---|
| Loss | -- |
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| Maintain | -- |
0 lbs (0 kg) |
| Gain | -- |
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This calculator uses the Mifflin-St Jeor equation (or Katch-McArdle if you enter body fat %) to calculate your BMR (Basal Metabolic Rate)—the calories you'd burn lying in bed all day. Then it multiplies by your activity level to get your TDEE (Total Daily Energy Expenditure).
The results show you three calorie targets: weight loss (20% calorie deficit), maintenance (eat what you burn), and weight gain (20% surplus).
Select your activity level carefully. The calculator multiplies BMR by activity level to determine TDEE, so accuracy here affects all results.
If you enter body fat percentage, we use the Katch-McArdle formula instead of Mifflin-St Jeor. Katch-McArdle is more accurate for lean individuals because it calculates BMR based on lean body mass rather than total weight. This means if you're muscular or very lean, the Katch-McArdle formula gives you a more precise calorie target since muscle burns more calories than fat.
Activity level selection is the most common miscalculation in calorie tracking. A desk job plus gym 3x/week equals lightly active, not moderate. Those three hours of exercise don't offset the 165 hours spent sitting. When calculating TDEE, consider your entire weekly routine rather than focusing on exercise time alone. If uncertain about which level fits your lifestyle, choose the lower option and adjust after tracking results for three weeks.
If your activity level already accounts for regular exercise (which it should), eating back "burned" calories creates a surplus and eliminates your deficit entirely. Don't eat exercise calories back, or eat back only half as a safety buffer to account for tracker overestimation.
Already lost 15 pounds? Your new lighter body needs fewer calories. What created a 500-calorie deficit at 200 lbs might be maintenance at 180 lbs. Recalculate every 10-15 pounds or when progress stalls for 3+ weeks despite consistent tracking.
Strict adherence during weekdays combined with untracked weekend eating often eliminates the weekly calorie deficit. Tracking only weekdays while ignoring weekend intake gives incomplete data. Track seven days per week or accept that weekend eating will slow your progress.
Common items like cooking oils, nuts, and bites of shared food often go untracked but contribute significant calories. These "small" items accumulate to hundreds of untracked calories daily. Using a food scale for two weeks reveals common portion estimation errors—most people underestimate portions significantly.
Daily weight fluctuations of 2-4 pounds from water retention are normal. You can gain 3 lbs overnight from sodium or lose 2 lbs from dehydration. The first 1-2 weeks of dieting often include significant water weight loss, especially on low-carb diets. Real fat loss averages 1-2 lbs per week after the initial drop.
Weigh yourself daily and track the weekly average rather than individual weigh-ins. Look at trends over 2-4 weeks instead of day-to-day changes. A moving average reveals actual progress while filtering out water weight noise.
Progress photos show body composition changes that scale weight doesn't reflect. When building muscle and losing fat simultaneously, scale weight may stay constant while body composition improves dramatically. Take photos from front, side, and back in consistent lighting at the same time of day.
Planning meals in advance reduces impulse eating when hungry. Making food decisions while hungry leads to higher-calorie choices. Pre-logging daily meals in the morning eliminates impulse decisions throughout the day.
Recalculate every 10-15 pounds of weight change. As you lose weight, your TDEE decreases because your smaller body requires fewer calories. What created a 500-calorie deficit at 200 lbs might be maintenance at 180 lbs. Also recalculate if your activity level changes significantly—starting or stopping a regular exercise routine affects your TDEE.
If your diet feels miserable after losing 20 lbs, you won't maintain it long-term. Building flexibility into your eating pattern beats rigid perfection. A sustainable approach you can follow for six months produces better results than an "optimal" diet you abandon after three weeks.
This calculator provides estimates for generally healthy adults. If you have thyroid disorders, PCOS, diabetes, or other metabolic conditions, your actual calorie needs may differ.
Consult your healthcare provider for personalized guidance if you have any medical conditions that affect metabolism or weight.