Should I eat back calories I burn during exercise?

Partially. If you're using the TDEE method (where your activity level already accounts for exercise), you don't need to add calories back. If you're using your BMR as the baseline and adding exercise on top, then yes - account for the calories burned during that specific workout. Most fitness apps use the TDEE method, so extra eating is rarely needed.

Calorie Deficit Calculator

Q: How many calories should I eat to lose 1 kg per week?

To lose 1 kg per week, you need a daily calorie deficit of approximately 1,100 calories (7,700 ÷ 7 days). This is aggressive - most people find a 500–750 calorie deficit more sustainable, resulting in 0.45–0.65 kg/week. Start with a moderate deficit to avoid hunger, muscle loss, and metabolic adaptation.

Find your ideal daily calorie target to lose weight safely - based on BMR, activity level, and goal.

Age

years

Weight

Height

Weight

Height

ft in

Activity Level

Weight Loss Goal

Daily Calorie Target

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calories/day

Your TDEE

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maintenance

Daily Deficit

—

cal/day below TDEE

Estimated Loss

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per week

BMR

—

at complete rest

Minimum Safe

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don't go below

🔥 What is a Calorie Deficit?

A calorie deficit is the state where you consume fewer calories than your body burns in a day. Your body requires energy - measured in calories - to power every bodily function: breathing, circulation, brain activity, digestion, movement, and exercise. The total amount of energy your body needs daily is called your Total Daily Energy Expenditure (TDEE).

When you consistently eat below your TDEE, your body must source the missing energy from stored reserves - primarily body fat. This is the fundamental mechanism of all fat loss. One kilogram of body fat stores approximately 7,700 calories of energy. A consistent daily deficit of 500 calories therefore depletes roughly 3,500 calories per week, translating to approximately 0.45–0.5 kg of fat loss per week.

Your TDEE is calculated from your Basal Metabolic Rate (BMR) - the calories burned at complete rest - multiplied by an activity factor. BMR is calculated using the Mifflin-St Jeor equation, which accounts for your weight, height, age, and biological sex. Activity factors range from 1.2 (sedentary, desk job) to 1.9 (very hard physical labour plus intense daily exercise).

The size of your deficit determines the rate of weight loss. A mild deficit of 250 calories/day produces slow but very sustainable loss of about 0.25 kg/week. A moderate deficit of 500 calories/day - the standard recommendation - targets 0.5 kg/week. An aggressive deficit of 750–1,000 calories/day accelerates loss to 0.75–1 kg/week but is harder to sustain, increases hunger, and risks muscle loss if protein intake is insufficient.

Importantly, your TDEE changes as you lose weight - a lighter body burns fewer calories at rest. Recalculate your targets every 4–6 weeks as you progress to ensure your deficit remains accurate and you continue losing weight at the expected rate.

📐 Calorie Deficit Formula

TDEE = BMR × Activity Factor

Daily Calorie Target = TDEE − Deficit

BMR (Male) = (10 × W) + (6.25 × H) − (5 × A) + 5

BMR (Female) = (10 × W) + (6.25 × H) − (5 × A) − 161

W = Weight (kg) | H = Height (cm) | A = Age (years)

500 cal deficit ≈ 0.5 kg weight loss per week (1 kg fat = 7,700 cal)

📖 How to Use This Calculator

Steps to Find Your Calorie Deficit Target

Select your gender, unit system, and enter your age, weight, and height accurately. Use morning weight without shoes.

Choose your activity level honestly. Most office workers should select Sedentary or Lightly Active - overestimating activity is the most common error.

Set your weight loss goal: Mild (0.25 kg/week) is easiest to maintain long-term. Moderate (0.5 kg/week) is the sweet spot for most people. Aggressive (0.75 kg/week) requires strong discipline.

Click Calculate to get your daily calorie target, TDEE, BMR, and minimum safe intake. Use this as your daily eating goal in any calorie-tracking app.

💡 Example Calculations

Example 1 - Male, 30 years, 85 kg, 178 cm, Moderately Active

BMR = (10 × 85) + (6.25 × 178) − (5 × 30) + 5 = 850 + 1112.5 − 150 + 5 = 1,817.5 cal/day

TDEE = 1,817.5 × 1.55 = 2,817 cal/day (maintenance)

Moderate deficit (500 cal): Daily target = 2,817 − 500 = 2,317 cal/day

Expected loss: ~0.5 kg/week. In 10 weeks: ~5 kg of fat loss (from 85 kg to ~80 kg).

Example 2 - Female, 28 years, 65 kg, 162 cm, Lightly Active

BMR = (10 × 65) + (6.25 × 162) − (5 × 28) − 161 = 650 + 1012.5 − 140 − 161 = 1,361.5 cal/day

TDEE = 1,361.5 × 1.375 = 1,872 cal/day

Mild deficit (250 cal): Daily target = 1,872 − 250 = 1,622 cal/day

Expected loss: ~0.25 kg/week. Minimum safe floor is 1,200 cal - the mild deficit is appropriate here as a 500-cal deficit would approach the minimum.

❓ Frequently Asked Questions

What is a calorie deficit and how does it cause weight loss?+

A calorie deficit occurs when you consume fewer calories than your body burns in a day (your TDEE). Your body compensates by burning stored energy - primarily body fat. One kilogram of body fat stores approximately 7,700 calories. A consistent deficit of 500 calories/day therefore causes roughly 0.5 kg of fat loss per week. This math is the universal basis of all fat loss, regardless of which specific diet you follow.

How many calories should I eat to lose 1 kg per week?+

To lose 1 kg per week requires a daily deficit of approximately 1,100 calories (7,700 ÷ 7 days). This is aggressive - most people find a 500–750 calorie deficit more sustainable and healthier, yielding 0.45–0.65 kg/week. Start with a moderate deficit to protect muscle mass, maintain energy, and build sustainable habits rather than forcing rapid loss.

Why did I stop losing weight even in a calorie deficit?+

Weight loss plateaus happen because: (1) your TDEE decreases as you lose body mass - recalculate every 4–6 weeks; (2) metabolic adaptation makes your body more efficient; (3) calorie underestimation (common when eating out); (4) water retention from stress, hormones, or high-sodium days can mask fat loss. Track trends over 2+ weeks using weekly averages, not individual daily weigh-ins.

What is the minimum safe calorie intake?+

General guidelines recommend not going below 1,200 calories/day for women and 1,500 calories/day for men without medical supervision. Below these thresholds, it becomes very difficult to meet nutritional needs, metabolism slows significantly, muscle is broken down for energy, and hormonal disruption can occur. This calculator shows your safe minimum floor so you never go below it.

Should I eat back exercise calories?+

If using the TDEE method (where your chosen activity level already accounts for regular exercise), you don't need to eat back workout calories. If you selected Sedentary but then did a 90-minute workout, you can add ~300–500 calories back to avoid too large a deficit that day. As a general principle, don't eat back more than 50% of estimated exercise calories, as calorie burn estimates are often inflated by 30–50%.

📌 Quick Tips

💡A deficit of 500 calories per day leads to approximately 0.5 kg weight loss per week (since 1 kg of fat ≈ 7,700 calories). A 1,000 cal deficit targets 1 kg/week, though this is aggressive and hard to sustain.

💡Avoid going below 1,200 calories/day for women or 1,500 calories/day for men. Severe restriction slows metabolism, causes muscle loss, and leads to nutrient deficiencies.

💡Protein is your best friend on a deficit. Eating 1.6–2.2 g of protein per kg of body weight preserves muscle mass while you lose fat - making the lost weight primarily fat, not muscle.

🔗 Related Calculators

📌 Quick Tips

💡Avoid going below 1,200 calories/day for women or 1,500 calories/day for men. Severe restriction slows metabolism, causes muscle loss, and leads to nutrient deficiencies.

💡Protein is your best friend on a deficit. Eating 1.6–2.2 g of protein per kg of body weight preserves muscle mass while you lose fat - making the lost weight primarily fat, not muscle.