TDEE Calculator UK — Total Daily Energy Expenditure

What Makes Up Your TDEE

Your total daily energy expenditure is composed of three main components. Basal Metabolic Rate accounts for 60 to 75 per cent of your total energy use and covers the essential biological processes that keep you alive. The thermic effect of food, the energy required to digest, absorb and metabolise what you eat, accounts for approximately 10 per cent. The remaining 15 to 30 per cent comes from physical activity, including both structured exercise and non-exercise activity such as walking, fidgeting and daily chores.

Non-exercise activity thermogenesis, or NEAT, can vary enormously between individuals. Someone with an active job who walks frequently throughout the day may burn 500 to 1,000 more calories through NEAT than a desk worker, even before considering any formal exercise. This is why activity level selection in the calculator makes such a significant difference to the result, and why choosing the most honest assessment of your daily activity is important for accuracy.

Using TDEE for Your Fitness Goals

For fat loss, eat 10 to 20 per cent below your TDEE for a moderate, sustainable deficit that preserves muscle mass. For muscle gain during a bulking phase, eat 10 to 15 per cent above your TDEE. For maintenance, aim to eat at or very close to your TDEE. These percentages provide more nuanced guidance than fixed calorie deficits or surpluses, because they scale appropriately with your individual energy needs.

Your TDEE is not a fixed number and will change as your weight, body composition, activity level and age change. Recalculate every four to six weeks if you are actively pursuing a weight goal, and adjust your calorie intake accordingly. If weight loss stalls despite consistent adherence to your calorie target, your TDEE may have decreased as your body has become smaller and more metabolically efficient, requiring a recalculation and modest reduction in intake or increase in activity.

TDEE and Exercise Planning

Understanding your TDEE helps you fuel your workouts appropriately. Undereating relative to your activity level impairs performance, recovery and immune function, while overeating promotes unwanted fat gain. Athletes and active individuals should pay particular attention to nutrient timing, consuming adequate carbohydrates before and after training to fuel performance and replenish glycogen stores, and sufficient protein throughout the day to support muscle repair.

Break down your calories into macronutrients with our macro calculator, or check your weight category using the BMI calculator. For NHS exercise and weight management advice, visit NHS Healthy Weight.