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🔥 Calorie Calculator

Calculate your daily calorie target for weight loss, maintenance, or gain. Uses the Mifflin-St Jeor equation to derive BMR and TDEE, then applies a deficit or surplus to your goal.

Daily Calorie Needs From Profile and Activity

BrainyCalculators editorial insight — unique to this tool

Combines anthropometrics and activity level into recommended intake — pregnancy, breastfeeding, and clinical conditions need clinician adjustment. Food labels in US use 2,000 kcal daily value; actual needs vary 1,600–3,000+ for adults. 1 kcal = 1 Calorie on US packaging (capital C).

When to use this calculator

Use for general daily calorie recommendation from demographics. Athletes may prefer TDEE with precise activity hours.

Need protein, carb, and fat gram targets?

This page gives a daily calorie target for your goal. To split those calories into macronutrient grams, use the Macro Calculator →

cm ft/in

What is a Calorie Calculator?

A calorie calculator estimates how many calories to eat each day to reach a goal — lose, maintain, or gain weight. It first computes your Basal Metabolic Rate (BMR) with the Mifflin-St Jeor equation, multiplies by an activity factor to get Total Daily Energy Expenditure (TDEE), then adjusts up or down for your target.

Use this page when your question is “how much should I eat?” It outputs a calorie number for maintenance plus deficit and surplus targets. A 500-calorie daily deficit yields roughly one pound of fat loss per week (3,500 calories ≈ 1 lb).

To split that calorie target into protein, carbohydrate, and fat grams, use the Macro Calculator. To see maintenance energy expenditure with activity multipliers only, use the TDEE Calculator; for resting burn alone, use the BMR Calculator.

Mifflin-St Jeor Formula

Male: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Female: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
TDEE = BMR × Activity Multiplier

The Mifflin-St Jeor equation is the most accurate BMR formula for most people, recommended by the Academy of Nutrition and Dietetics.

How to Use This Calculator

  1. 1
    Select Your Gender
    The calorie formula differs between males and females due to body composition differences.
  2. 2
    Enter Age & Measurements
    Enter your age, height, and weight. You can switch between metric (cm/kg) and imperial (ft/lbs) units.
  3. 3
    Choose Activity Level
    Pick the activity level that best matches your typical week — be honest for the most accurate result.
  4. 4
    Read Your Calorie Targets
    The calculator shows your BMR, maintenance calories, and targets for weight loss or gain.

Real-World Example

Male, 30 years, 175 cm, 75 kg, Moderately Active (×1.55):

BMR = 10×75 + 6.25×175 − 5×30 + 5 = 1,771 cal/day
TDEE = 1,771 × 1.55 = 2,745 cal/day
Mild loss (−0.5 kg/wk) = 2,245 cal/day
Weight loss (−1 kg/wk) = 1,745 cal/day
Weight gain (+0.5 kg/wk) = 3,245 cal/day

How the Calorie Calculator Works

Formula, assumptions, and calculation steps for this health tool.

Formula Used

Daily Calories = BMR * Activity Factor +/- Goal Adjustment

Methodology

Health calculators use published screening formulas and common planning rules to estimate body, nutrition, pregnancy, or fitness metrics from user inputs.

Calculation Steps

  1. Enter the personal measurements requested by the tool.
  2. Convert height, weight, age, dates, or activity inputs to standard units.
  3. Apply the health or fitness formula for the selected metric.
  4. Show the estimate with practical ranges or interpretation where available.

Assumptions and Limits

  • Results are educational estimates, not diagnosis or medical advice.
  • Individual factors such as medication, pregnancy, and medical history can change interpretation.
  • Consult a clinician for personal health decisions.

Reference basis: Common public-health and sports-science screening formulas.

Frequently Asked Questions

BMR (Basal Metabolic Rate) is the number of calories your body needs to maintain basic physiological functions — breathing, circulation, and cell production — while completely at rest. It is the minimum energy your body requires to survive.

TDEE (Total Daily Energy Expenditure) is the total number of calories you burn in a day, including all physical activity. It equals your BMR multiplied by an activity factor ranging from 1.2 (sedentary) to 1.9 (extra active).

A deficit of 500 calories per day leads to roughly 0.5 kg (1 lb) of fat loss per week. A 1,000 calorie deficit targets 1 kg (2 lbs) per week. Avoid going below 1,200 cal/day for women or 1,500 cal/day for men without medical supervision.

Men generally have more muscle mass and less body fat than women of the same weight and height. Muscle tissue burns more calories at rest, so men typically have a higher BMR. The Mifflin-St Jeor formula accounts for this with gender-specific constants (+5 for men, −161 for women).

The Mifflin-St Jeor equation is the most validated BMR formula and accurate within ±10% for most people. Individual variation in metabolism, genetics, hormones, and gut microbiome can affect actual needs. Use this as a starting point and adjust based on real-world results over 2–4 weeks.

Real-World Applications

⚖️
Weight Loss Planning
Find your maintenance TDEE, then subtract 500–750 calories to create a safe deficit targeting 0.5–0.75 kg loss per week.
💪
Muscle Building
Eat 250–500 calories above TDEE to fuel muscle growth with adequate protein (1.6–2.2 g/kg body weight).
🏃
Athletic Training
Athletes use TDEE to ensure adequate fuelling for training, avoiding under-eating that impairs performance and recovery.
🥗
Meal Planning
Set daily calorie and macro targets to plan structured meals that meet energy needs without guesswork.
💊
Clinical Nutrition
Dietitians use BMR/TDEE to calculate prescribed calorie targets for hospital patients, eating disorder recovery, or post-surgery nutrition.
🎯
Body Recomposition
Eating at or near maintenance while lifting weights allows gradual fat loss and muscle gain simultaneously.

Advantages

  • ✓ Evidence-based starting point validated across diverse populations
  • ✓ Quick and free — no lab tests or equipment needed
  • ✓ Personalised by weight, height, age, sex, and activity
  • ✓ Provides multiple targets for loss, maintenance, and gain

Limitations

  • ✗ Cannot account for individual metabolic variation (±10–15%)
  • ✗ Activity multipliers are estimates — overestimating activity is common
  • ✗ Does not consider hormones, gut microbiome, or sleep quality
  • ✗ Calorie counts on food labels have up to 20% measurement error

Common Calorie Calculation Mistakes

1
Overestimating Activity Level
Most people select "Moderately Active" when their actual week is closer to "Sedentary." Overestimating by one level adds ~300 calories/day — enough to prevent weight loss.
2
Cutting Calories Too Aggressively
Deficits exceeding 1,000 cal/day trigger muscle loss, hormonal changes, and metabolic adaptation. Sustainable loss requires patience, not extreme restriction.
3
Not Tracking Liquid Calories
Sodas, juices, alcohol, and coffee drinks can add 300–700 calories per day that are easy to overlook if only tracking solid food.
4
Assuming All Calories Are Equal
While total calories drive weight change, protein and fibre improve satiety and muscle retention. Eating 2,000 calories of protein is very different from 2,000 calories of sugar.
5
Not Adjusting as Weight Changes
As body weight drops, BMR decreases and you burn fewer calories. Recalculate every 5 kg of weight change to keep the calorie target accurate.

Calorie Deficit vs. Expected Weight Loss

Daily Deficit Weekly Loss Monthly Loss Sustainability
250 cal ~0.25 kg ~1 kg Very sustainable, minimal hunger
500 cal ~0.5 kg ~2 kg Recommended — safe and manageable
750 cal ~0.75 kg ~3 kg Moderate — requires discipline
1,000 cal ~1 kg ~4 kg Aggressive — some muscle loss risk
1,500 cal ~1.5 kg ~6 kg Not recommended — metabolic slowdown

References

  1. Mifflin, M.D. et al. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990.
  2. Academy of Nutrition and Dietetics. Position Paper: Total Diet Approach to Healthy Eating. eatright.org
  3. U.S. Department of Agriculture. Dietary Guidelines for Americans, 2020–2025. dietaryguidelines.gov
  4. Hall, K.D. et al. Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction. Cell Metabolism, 2015.
  5. Trexler, E.T. et al. Metabolic adaptation to weight loss. Journal of the International Society of Sports Nutrition, 2014.

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