Calorie Calculator
Calculate your daily calorie needs based on age, weight, height, sex, and activity level. Uses the Mifflin-St Jeor equation.
Mifflin-St Jeor Equation.
The most accurate formula for estimating BMR (Basal Metabolic Rate):
Female: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161
Multiply BMR by activity factor (1.2–1.9) to get TDEE (Total Daily Energy Expenditure).
Your Guide to Daily Calorie Calculations
A Calorie Calculator is an essential tool for understanding your daily energy needs and tailoring your diet to meet specific fitness goals. Calories are units of energy that our bodies extract from macronutrients (proteins, carbohydrates, and fats) to fuel physical movement, cellular repair, and basal metabolic survival. By calculating your daily energy needs, you can make informed decisions about portion sizes, nutritional splits, and training regimens without resorting to extreme, unsustainable diets.
The Science of Energy Balance & TDEE
The calculator estimates your Total Daily Energy Expenditure (TDEE) by first computing your Basal Metabolic Rate (BMR) and then applying an activity multiplier. Your BMR represents the energy consumed at rest, while the activity multiplier accounts for the energy expended during work, daily movement, and structured exercise. Under the thermodynamic principle of energy balance, maintaining weight requires eating calories equal to your TDEE. Consuming fewer calories forces your body to burn stored fat for fuel, whereas a calorie surplus provides the surplus energy necessary for muscle hypertrophy.
Macronutrient Targets & Goal Customization
To optimize body composition during a weight shift, it is important to track not just total calories, but also macronutrient ratios. Sufficient protein intake (approx. 1.6–2.2g per kg of body weight) is critical for sparing muscle mass in a deficit and building muscle in a surplus. Carbohydrates fuel high-intensity exercise and replenish muscle glycogen, while dietary fats regulate endocrine health and vitamin absorption. This calculator helps distribute your calories across these macros to support optimal energy levels and athletic performance.
Frequently Asked Questions
The calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then multiplies it by your selected activity level factor (1.2 to 1.9) to produce your Total Daily Energy Expenditure (TDEE). This gives the calories needed to maintain your current weight.
A safe calorie deficit for weight loss is 500–750 calories below your TDEE per day, which translates to roughly 0.5–0.75 kg (1–1.5 lbs) of weight loss per week. Cutting more than 1,000 calories per day is generally not recommended without medical supervision, as it can cause muscle loss and nutrient deficiencies.
Choose the level that honestly reflects your average weekly activity: Sedentary (desk job, little or no exercise), Lightly Active (light exercise 1–3 days/week), Moderately Active (moderate exercise 3–5 days/week), Very Active (hard exercise 6–7 days/week), or Extra Active (very hard exercise plus physical job). Overestimating your activity level is one of the most common reasons calorie estimates are inaccurate.
Yes. If your goal is muscle gain, you should eat a calorie surplus of approximately 250–500 calories above your TDEE per day. Combined with resistance training, this surplus provides the energy substrate needed for muscle protein synthesis without excessive fat gain.
Calorie calculators provide estimates based on population averages. Individual metabolism varies due to genetics, hormone levels, gut microbiome, sleep quality, and stress. Water retention, menstrual cycles, and muscle gain can also mask fat loss on the scale. Track trends over 2–4 weeks rather than daily fluctuations for accurate progress.