Calorie Calculator
Calculate your daily calorie requirement using the Mifflin-St Jeor formula. Based on age, height, weight, gender and activity level.
About the Calorie Calculator
A calorie calculator estimates your daily energy expenditure and recommends caloric intake targets for weight maintenance, healthy fat loss, or lean muscle gain. The calculation is grounded in the scientifically validated Mifflin-St Jeor equation, recognized by clinical dietitians as the most accurate formula for estimating Basal Metabolic Rate (BMR).
Your Basal Metabolic Rate represents the calories burned purely to sustain vital physiological functions at complete rest (breathing, cardiac function, cellular repair). This baseline is then multiplied by a Physical Activity Level (PAL) coefficient ranging from 1.2 for sedentary lifestyles up to 1.9 for rigorous athletic training to arrive at your Total Daily Energy Expenditure (TDEE).
To lose approximately one pound (0.45 kg) of body fat per week, a sustainable caloric deficit of roughly 500 kcal per day below your TDEE is standard. Severe caloric restriction below your BMR is counterproductive, as it triggers metabolic slowdown and muscle catabolism.
A 32-year-old male weighing 80 kg and 180 cm tall has a calculated BMR of approximately 1,775 kcal. With moderate exercise 3-5 days weekly (activity factor 1.55), his TDEE is roughly 2,750 kcal. For gradual fat loss, targeting 2,250 kcal daily creates a healthy 500 kcal deficit.
Tips for best results
- Recalculate your caloric requirements as your body weight changes, since a lighter body requires fewer calories to maintain and move.
- Prioritize protein intake (1.6 to 2.2 grams per kilogram of body weight) during a caloric deficit to preserve lean muscle tissue and enhance satiety.
- Track calorie intake consistently using a digital kitchen scale for several days to eliminate unconscious portion underestimation.
How to use the Calorie Calculator
Why use Toolseza for Calorie Calculator?
Use this tool as often as you need with no paywalls, premium tiers, or hidden daily calculation quotas.
All calculations and file manipulations run inside your web browser. Your inputs are never sent to a cloud server.
Results update in real-time as you type or adjust settings, with instant one-click copy and export capabilities.
Works natively on smartphones, tablets, laptops, and desktop computers with zero installation or account creation.
Editorial Standards & Verification: All formulas, algorithms, and conversion factors implemented on Toolseza adhere to openly documented international standards (ISO, NIST, BIPM, W3C). Results are verified against benchmark reference datasets before publication.
Frequently Asked Questions
Is Calorie Calculator free to use?
Yes — Calorie Calculator is completely free, unlimited, and requires no sign-up.
How many calories should I eat to lose weight?
A deficit of roughly 500 calories per day leads to approximately 0.5 kg (1 lb) of weight loss per week. Always consult a healthcare professional before making significant dietary changes.
Are the calculations accurate?
Yes — it uses the standard, widely accepted formula, so results are accurate and reliable.
Does it work on mobile and tablet?
Yes — Calorie Calculator works on any modern browser, including mobile and tablet, no app required.