Find your Basal Metabolic Rate, daily calorie burn (TDEE), and a calorie target for losing, maintaining, or gaining weight — with a macro breakdown to match.
This calculator finds your Basal Metabolic Rate (BMR), your Total Daily Energy Expenditure (TDEE) based on activity level, and a calorie target with a macro breakdown for losing, maintaining, or gaining weight. Enter your details and results appear instantly, right in your browser, with no sign-up required.
BMR is the number of calories your body burns at complete rest just to keep essential functions running — breathing, circulation, cell repair, and basic organ function. It does not include any calories burned through movement or exercise. BMR typically makes up 60–75% of total daily calorie burn for most people, which is why it's the foundation every calorie goal is built from.
TDEE (Total Daily Energy Expenditure) takes BMR and adds in calories burned through daily activity, from light movement to structured exercise. This calculator shows both: your BMR at complete rest, your "sedentary burn" (BMR with minimal daily movement factored in), and your full TDEE based on the activity level you select. TDEE is the number most people use as their maintenance calorie baseline.
By default, this calculator uses the Mifflin-St Jeor formula, widely considered the most accurate general-purpose BMR equation. If you enter your body fat percentage, it automatically switches to the Katch-McArdle formula instead, which calculates BMR from lean body mass rather than total weight — this tends to be more precise for people who know their body composition, especially those with more or less muscle than average.
Once a calorie goal is calculated, the macro split adjusts protein, carbohydrate, and fat targets based on that goal. A weight-loss target leans higher in protein to help preserve muscle during a calorie deficit. A weight-gain target shifts more calories toward carbohydrates to support training and recovery. Maintenance uses a balanced, moderate split across all three. Gram targets are calculated using standard conversions: 4 calories per gram of protein and carbohydrate, and 9 calories per gram of fat.
What is BMR? BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep basic functions like breathing, circulation, and cell production running.
What is the difference between BMR and TDEE? BMR is calories burned at complete rest, while TDEE adds in calories burned through daily activity and exercise, giving your true total daily calorie burn.
How is BMR calculated? This calculator uses the Mifflin-St Jeor formula by default, or the Katch-McArdle formula if you enter your body fat percentage, which uses lean body mass for a more precise estimate.
How accurate is a BMR calculator? BMR formulas are estimates and individual metabolism can vary roughly 10-15% from the calculated number due to genetics, muscle mass, and other factors. Use it as a starting point, not an exact figure.
Why does the macro split change based on my goal? Protein needs increase relative to calories during weight loss to help preserve muscle, while weight gain shifts more calories toward carbohydrates to fuel training — maintenance uses a balanced default split.
Is this BMR calculator free? Yes, it is completely free with no sign-up required, and runs instantly in your browser.
Does this store or upload my data? No — the calculation runs entirely in your browser. Nothing is sent to any server.
Disclaimer: This tool provides a general estimate only and is not a substitute for professional medical or nutritional advice. Always consult a qualified healthcare provider or registered dietitian before starting a new diet or weight management plan.