Use this calorie calculator to estimate your daily calorie needs for maintaining, losing, or gaining weight. It uses the widely respected Mifflin–St Jeor equation for BMR and adjusts for your activity level to provide a personalized Total Daily Energy Expenditure (TDEE).
What this calorie calculator does
This tool estimates your Basal Metabolic Rate (BMR) — the calories your body burns at rest — and multiplies it by an activity factor to calculate your Total Daily Energy Expenditure (TDEE). Based on your goal, it then suggests a daily calorie target to maintain, lose, or gain weight. For weight change goals, the calculator applies a moderate 500 kcal/day adjustment, a commonly used starting point for sustainable progress.
How the calculation works
The calculator uses the Mifflin–St Jeor formula, regarded by many dietitians and researchers as a practical, accurate method for estimating BMR in adults:
- For men: BMR = 10 × weight (kg) + 6.25 × height (cm) ? 5 × age + 5
- For women: BMR = 10 × weight (kg) + 6.25 × height (cm) ? 5 × age ? 161
Your TDEE is then estimated as BMR multiplied by an activity factor that reflects your lifestyle, ranging from sedentary (1.2) to extra active (1.9). The result is a realistic daily calorie budget for the average day.
Activity level guide
- Sedentary: Little to no exercise, mostly seated work.
- Lightly active: Light exercise 1–3 days per week.
- Moderately active: Moderate exercise 3–5 days per week.
- Very active: Hard exercise 6–7 days per week.
- Extra active: Very hard exercise or a physically demanding job.
How to use the calculator
- Enter your age and biological sex.
- Provide your height and weight (use your preferred units).
- Select your typical activity level.
- Choose your goal: maintain, lose, or gain weight.
- Submit to see your BMR, TDEE, and a suggested daily calorie target.
What do the results mean?
BMR tells you the baseline calories your body needs for essential functions. TDEE is your estimated daily burn including movement. If you choose “maintain,” your daily target will match TDEE. For “lose,” you’ll see a modest deficit (about 500 kcal/day), which often translates to roughly 0.45 kg (1 lb) of weight loss per week. Likewise, “gain” applies a similar surplus to encourage gradual, sustainable muscle and weight gain.
Tips for accuracy
- Use recent, accurate measurements for height and weight.
- Choose the activity level that best reflects your weekly average, not a single day.
- Recalculate as your weight or routine changes.
- Remember: all calculators are estimates. Track your progress and adjust calories if your real-world results differ.
Frequently asked questions
Is Mifflin–St Jeor accurate?
It’s among the most validated formulas for healthy adults. Still, individual metabolism varies, so treat it as a starting point and fine-tune based on outcomes.
Should I change calories on workout days?
You can keep a steady daily target (based on average activity) or use calorie cycling. Consistency is simpler for most people, while cycling may better match heavy training days.
Do I need to track macros?
Calories drive weight change, but protein, carbs, and fats improve satiety, performance, and body composition. If you choose to track macros, ensure adequate protein and balanced carbs and fats to support your goals.
Use this calorie calculator to set a smart baseline. Combine it with mindful nutrition, regular activity, and periodic check-ins to steer your plan toward sustainable success.