Your brain burns roughly 300–400 kcal per day — about 20% of your resting metabolism — and thinking harder barely changes it.
Your brain burns roughly 300–400 kcal per day — about 20% of your resting metabolism — and thinking harder barely changes it.
What does science say?
Your brain burns roughly 300–400 kcal per day — about 20% of your resting metabolism — and thinking harder barely changes it.
kcal for common activities · 70 kg
kcal in 30 min · 70 kg · Your Brain = highlighted
All values use the MET approach from the Compendium of Physical Activities (Ainsworth et al. 2011) and the ACSM formula. Figures are gross calories (including resting metabolism) — individual variation due to fitness level, technique, temperature, and metabolic efficiency can be ±20–30%.
For more precise measurements, heart-rate-based devices or lab testing (indirect calorimetry) are recommended.
Calories are burned primarily by physical work — muscles converting energy. Resting metabolism (Basal Metabolic Rate, BMR) accounts for 60–75% of an average adult's daily energy expenditure. Movement, exercise, and everyday activity (NEAT — Non-Exercise Activity Thermogenesis) make up the rest.
No single activity dramatically elevates burn in isolation — what matters is the sum of all activity throughout the day.
Your brain burns roughly 300–400 kcal per day — about 20% of your resting metabolism — and thinking harder barely changes it.
Yes. Many half-truths circulate about Your Brain. The section above explains what the science actually says.
For some of these concepts (e.g. resting metabolism, muscle calories) weight does matter; for others (e.g. sweating) it barely does.
Combining cardiovascular exercise (running, cycling, swimming) with strength training and a moderate calorie deficit is the evidence-based approach.
The values are based on the Compendium of Physical Activities (Ainsworth et al. 2011) and the ACSM formula. Individual variation (fitness level, efficiency, temperature) can account for ±20–30%.
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The calorie calculator supports all activities with adjustable weight and duration.