CALORIECALCULATOR
Work out how many calories you need each day to maintain, lose or gain weight — based on your body stats and activity level.
Your Details
What Is a Calorie Calculator?
A calorie calculator estimates how many calories your body needs each day. It uses your age, height, weight, sex and activity level to calculate two key numbers: your BMR (Basal Metabolic Rate) — the calories you burn doing absolutely nothing — and your TDEE (Total Daily Energy Expenditure) — the total calories you burn including exercise and daily movement. Once you know your TDEE, you know how much to eat to maintain, lose or gain weight.
How This Calculator Works
We use the Mifflin-St Jeor equation, which is considered the most accurate formula for estimating BMR in healthy adults. It was published in 2005 and is recommended by the Academy of Nutrition and Dietetics over older formulas like Harris-Benedict.
Enter Your Body Stats
Pop in your age, sex, height and weight. You can switch between metric (cm/kg) and imperial (feet-inches/stone-lbs) — the calculator converts everything behind the scenes.
Pick Your Activity Level
Be honest here. Most desk workers are 'sedentary' or 'lightly active' even if they exercise a few times a week. Overestimating activity is the most common mistake people make.
Get Your Numbers
The calculator shows your BMR, your maintenance calories (TDEE), a weight-loss target (TDEE minus 500 kcal) and a weight-gain target (TDEE plus 500 kcal). A 500 calorie deficit works out to roughly 0.5 kg of fat loss per week.
Mifflin-St Jeor Equation
The equation estimates BMR from lean body metrics. TDEE is then calculated by multiplying BMR by an activity factor: 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active), or 1.9 (extra active). For example, a 30-year-old male who is 180 cm, 80 kg and moderately active: BMR = 10×80 + 6.25×180 − 5×30 + 5 = 1,780 kcal. TDEE = 1,780 × 1.55 = 2,759 kcal.
Tips & Best Practices
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If you are not sure about your activity level, pick the lower option — most people overestimate how active they really are
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A 500 calorie deficit is sustainable for most people. Going much lower than that tends to backfire within weeks
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Weigh yourself at the same time each day (ideally first thing in the morning) and track the weekly average, not individual readings
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Your TDEE is not fixed — it changes as you lose or gain weight, so recalculate every 5–10 kg
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Protein is the most filling macronutrient. Eating enough protein (around 1.6–2.2 g per kg of body weight) helps preserve muscle during a deficit
Frequently Asked Questions
Mandeep Singh · 25+ Years UK Financial Services
Important Information
This calculator is for informational purposes only and does not constitute financial advice or a personal recommendation.
Results are estimates based on the information you provide and may not reflect your actual financial position.
You should consider seeking independent professional advice tailored to your specific circumstances before making any financial decision.