TDEE & Calorie Calculator
Find out how many calories your body burns each day — then work out exactly how much to eat to lose weight, maintain, or build muscle. Uses the Mifflin-St Jeor formula. Free, no account needed.
What is TDEE?
Total Daily Energy Expenditure (TDEE) is simply the total number of calories your body burns in a day — your resting metabolism, the energy it takes to digest food, and everything you do physically. Eat at this number and your weight stays roughly the same.
- Eat below TDEE — weight loss
- Eat at TDEE — maintain current weight
- Eat above TDEE — weight or muscle gain
Activity Level Guide
| Level | Multiplier | Example |
|---|---|---|
| Sedentary | ×1.2 | Office job, no gym |
| Lightly active | ×1.375 | Walk 20–30 min/day |
| Moderately active | ×1.55 | Gym 3–5 days/week |
| Very active | ×1.725 | Daily hard training |
| Extra active | ×1.9 | Physical job + gym |
Why Mifflin-St Jeor?
This calculator uses the Mifflin-St Jeor equation, which nutrition researchers consider the most accurate general-population BMR formula. It factors in your age, height, weight, and biological sex — and it tends to land within 10% of a measured result for most people.
How Big a Deficit Is Safe?
A 500 calorie daily deficit leads to roughly 0.5 kg of weight loss per week — sustainable and sensible. Going below 1,200 cal/day (women) or 1,500 cal/day (men) is not advisable without medical supervision, as it risks muscle loss and nutrient deficiencies.
Don't Ignore Protein
Calories matter, but so does what those calories are made of. Getting enough protein — roughly 1.6–2g per kg of body weight — is what keeps you from losing muscle alongside fat whilst in a deficit. Carbs and fats can be adjusted around that.
Frequently Asked Questions
BMR (Basal Metabolic Rate) is the number of calories your body burns just to keep you alive — heart beating, lungs breathing, kidneys filtering. It assumes you're lying completely still all day. TDEE takes your BMR and adds everything else: the walking, the gym sessions, the energy used digesting your food. It's the number your diet should be based around, not BMR.
Take 300–500 calories off your TDEE for steady, sustainable loss — roughly 0.3–0.5 kg per week. That pace feels slow, but it's the kind of loss you actually keep. Cutting 750 a day is possible but harder to stick to. Anything over 1,000 below TDEE risks muscle loss, exhaustion, and nutrient gaps — don't go there without guidance from a dietitian or your GP.
As your weight drops, your body has less mass to maintain — so your BMR falls too. This is sometimes called metabolic adaptation, and it's the reason most people hit a plateau after a few months of dieting. Recalculate your TDEE every 4–6 weeks, or whenever you've lost 4–5 kg, and adjust your calorie target accordingly.
Eating 200–300 calories above your TDEE — combined with consistent resistance training — is the sweet spot for lean muscle gain. A small surplus keeps fat gain minimal. The "dirty bulk" approach (eating well above TDEE) tends to just add fat; the muscle gains are similar but you have more to lose afterwards.
For most people it'll land within 10–15% of their actual energy needs — which is close enough to be genuinely useful. That said, individual metabolism varies quite a bit depending on genetics, hormones, gut health, and any medications you're taking. Treat the result as a starting point. Track your weight for two weeks, and if it's moving faster or slower than expected, adjust by 100–200 calories and reassess.
Disclaimer: The information provided on this page is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or qualified health provider with any questions regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.