Standing vs Sitting Calculator

Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a 24-hour period, combining your Basal Metabolic Rate (BMR) — the calories required to sustain basic biological functions at rest — with the additional calories burned through physical activity, digestion (the thermic effect of food), and NEAT (non-exercise activity thermogenesis: fidgeting, standing, walking). TDEE is the essential reference for any diet or fitness goal: consuming below TDEE causes weight loss; above it, weight gain; at it, weight maintenance. and are companion tools for building a complete nutrition and energy plan.

TDEE is not a fixed number. It fluctuates daily with activity level, changes over time with shifts in body composition (muscle burns more than fat at rest), and adapts during prolonged calorie restriction — the body reduces BMR defensively during sustained deficits, a phenomenon called metabolic adaptation. This is why calorie deficits often produce slower results than expected after the first few weeks.

1. Enter your weight in kg or lbs, and your height in cm or feet/inches.
2. Enter your age — BMR declines with age as lean muscle mass typically decreases.
3. Select your sex — females typically have lower BMR than males at the same height and weight due to lower average muscle mass.
4. Select your activity level using the Harris-Benedict or Mifflin-St Jeor activity multipliers: sedentary (1.2), lightly active (1.375), moderately active (1.55), very active (1.725), extra active (1.9).
5. Read your TDEE from the result card — this is the maintenance calorie level for your current activity.
6. Subtract 250–500 kcal/day for a moderate fat loss rate of 0.25–0.5 kg/week; add 250–500 kcal/day to gain lean mass.

TDEE and BMR formulas explained

Mifflin-St Jeor BMR (recommended):

Male: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5

Female: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161

TDEE = BMR × Activity Multiplier

Worked example: 30-year-old male, 80 kg, 180 cm, moderately active. BMR = (10×80) + (6.25×180) − (5×30) + 5 = 800 + 1,125 − 150 + 5 = 1,780 kcal. TDEE = 1,780 × 1.55 = 2,759 kcal/day. For 0.5 kg/week fat loss: target 2,259 kcal/day (500 kcal deficit).

Understanding your TDEE result

Activity multiplier reference guide

Sedentary (×1.2): desk job, minimal exercise. Lightly active (×1.375): light exercise 1–3 days/week. Moderately active (×1.55): moderate exercise 3–5 days/week. Very active (×1.725): hard exercise 6–7 days/week or physical job. Extra active (×1.9): very hard exercise/sports + physical labour job. Most people significantly overestimate their activity level — when in doubt, use the lower multiplier. A TDEE result that feels too high probably is; track actual intake vs weight change for 2–3 weeks to calibrate the true maintenance level.

Health tips and best practices

• Track your weight daily and take a 7-day average — day-to-day weight fluctuates by 1–2 kg due to water, glycogen, and food content. The weekly trend reveals true direction.
• TDEE calculations from formulas are estimates with ±15% error for individuals — real-world validation over 2–4 weeks is more reliable for personal calorie targets.
• Increasing muscle mass through resistance training raises BMR — each kg of added muscle increases daily calorie burn by approximately 13 kcal/day, compounding over time.
• Protein has the highest thermic effect of food (~30% of calories consumed): eating 200 kcal of protein effectively costs only 140 net kcal, which is why high-protein diets support fat loss.
• Diet breaks (returning to maintenance calories for 1–2 weeks) during a prolonged deficit help counteract metabolic adaptation and improve adherence.
• NEAT (non-exercise activity) is highly variable and often the largest driver of TDEE differences between individuals of similar size and exercise habits — walking more throughout the day can add 200–500 kcal to TDEE.

• Average TDEE for a moderately active 35-year-old male in the UK: approximately 2,600–2,800 kcal/day. For a female: approximately 2,000–2,200 kcal/day.
• BMR accounts for 60–75% of total TDEE; physical activity 15–30%; thermic effect of food (digestion) approximately 10%.
• A 3,500 kcal deficit is the traditional estimate for 0.45 kg (1 lb) of fat loss — though research shows this is an approximation and actual results vary significantly by individual.
• Elite endurance athletes (Tour de France cyclists) can have TDEEs exceeding 8,000–10,000 kcal/day during multi-stage racing (Volek & Phinney research).

Common mistakes to avoid

• Overestimating activity level — most desk workers who exercise 3 days/week are "lightly active" rather than "moderately active"; the difference is ~200 kcal/day in TDEE.
• Using TDEE as a static target — TDEE decreases as weight loss occurs, because a lighter body burns fewer calories. Recalculate every 4–6 kg of weight change.
• Ignoring liquid calories — drinks account for 200–400 kcal/day for many people and are frequently omitted from tracking.
• Treating TDEE formulas as perfectly accurate — individual metabolic variation means actual maintenance intake can differ from the calculated TDEE by 15–20% in either direction.

TDEE and calorie calculations are based on published BMR formulas (Mifflin-St Jeor, 1990) and standard activity multipliers. These are population-level estimates and may not accurately reflect individual metabolic rates. This calculator does not constitute dietary, nutritional, or medical advice. Significant dietary changes, especially those involving large calorie deficits, should be discussed with a registered dietitian (RD) or GP, particularly for individuals with existing health conditions, those who are pregnant or breastfeeding, or athletes with high performance requirements.