GetHealthyCalculators
Skip to content

Calorie Calculator

This calorie calculator estimates the number of calories you should eat each day to reach your weight goal. It first calculates your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation, then adjusts based on whether you want to lose, maintain, or gain weight.

Quick Answer

To lose weight, eat 500 calories below your TDEE for ~1 lb/week loss. To gain, eat 250–500 above it. Most adults need 1,600–3,000 calories per day.

These results are estimates based on general formulas and are not a substitute for professional medical advice. Consult a healthcare provider before making health decisions.

Enter your details above to calculate your daily calorie goal.

How the Formula Works

  1. Calculate your BMR using the Mifflin-St Jeor equation.

    Males: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 Females: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
  2. Multiply BMR by your activity level to get your TDEE.

    TDEE = BMR × Activity Multiplier
  3. Apply a calorie adjustment based on your weight goal.

    Mild deficit: −250 cal/day | Moderate deficit: −500 cal/day | Aggressive deficit: −750 cal/day Mild surplus: +250 cal/day | Moderate surplus: +500 cal/day
  4. Estimate weekly weight change using the 3,500 calorie rule.

    Weekly Change (lbs) = (Daily Adjustment × 7) ÷ 3,500

Methodology & Sources

Reviewed and updated March 28, 2026 · Prepared by GetHealthyCalculators Editorial Team

This calculator estimates maintenance calories from the Mifflin-St Jeor equation and standard activity multipliers, then applies a fixed deficit or surplus. It is intended for practical planning, not exact prediction of weekly scale changes.

References

  • A new predictive equation for resting energy expenditure in healthy individuals · American Journal of Clinical Nutrition
  • Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults · National Institutes of Health

Limitations

  • The 3,500 calorie rule is a simplified estimate — actual weight change depends on metabolic adaptation over time.
  • Individual metabolism varies based on genetics, hormones, sleep, and stress levels.
  • Aggressive calorie deficits (over 750 cal/day) may not be sustainable and can affect energy, mood, and muscle mass.
  • This calculator does not account for specific macronutrient needs or meal timing.

Frequently Asked Questions

How many calories should I eat to lose weight?
To lose weight, you need to eat fewer calories than your body burns (a caloric deficit). A moderate deficit of 500 calories per day is commonly recommended, which typically results in about 1 pound of weight loss per week.
What is a calorie deficit?
A calorie deficit occurs when you consume fewer calories than your Total Daily Energy Expenditure (TDEE). Your body then uses stored energy (body fat) to make up the difference, resulting in weight loss over time.
Is a 500 calorie deficit safe?
A 500 calorie per day deficit is generally considered safe and sustainable for most healthy adults. It leads to approximately 1 pound of weight loss per week. However, very low calorie diets should be supervised by a healthcare provider.
How does activity level affect my calorie needs?
More physically active people burn more calories throughout the day, which increases their TDEE. This means they can eat more calories while still maintaining or losing weight compared to someone who is sedentary.
Should I eat back the calories I burn during exercise?
Your TDEE already factors in your general activity level. If you do additional exercise beyond your selected activity level, you may want to eat back some of those extra calories to avoid too large a deficit, especially if you feel fatigued.
What should I do if my weight loss stalls?
First, confirm consistency with calorie intake, protein, and activity. If progress has truly stalled for multiple weeks, recalculate your TDEE at your current body weight and consider a smaller adjustment rather than making a dramatic cut.
How low is too low for calories?
Very low calorie intakes can make dieting harder to sustain and may increase fatigue, nutrient gaps, and muscle loss risk. If your target feels excessively restrictive, it is usually better to slow the pace of loss than to force a very aggressive deficit.

Distribute your calories across protein, carbs, and fat

Macro Calculator

More on This Topic