How Many Calories to Lose Weight? (Calculator + Chart)

The answer to "how many calories to lose weight" is not a single number — it's a formula based on your body, your goals, and how fast you want to lose. The good news: the science is well-established and the calculation takes under 60 seconds.

This guide explains BMR, TDEE, and the right deficit to create — with a working calculator you can use right now. No guesswork. No extremes.

📋 Table of Contents

What is BMR?
What is TDEE?
Free Calorie Calculator
How Big Should Your Deficit Be?
Deficit vs. Weight Loss Chart
Real-World Examples
3 Common Calorie Mistakes
FAQs

Step 1: Calculate Your BMR (Basal Metabolic Rate)

Your BMR is the number of calories your body burns at complete rest — just to keep organs functioning, blood circulating, and breathing going. It accounts for 60–70% of your total daily calorie burn [1].

The most accurate formula for non-athletes is the Mifflin-St Jeor equation, validated in a 2005 review as the most precise for healthy adults [2]:

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

For example, a 30-year-old woman who weighs 70 kg and is 165 cm tall has a BMR of: (10 × 70) + (6.25 × 165) − (5 × 30) − 161 = 1,445 kcal/day.

Step 2: Find Your TDEE (Total Daily Energy Expenditure)

Your BMR only tells you the bare minimum. Your TDEE is what you actually burn each day, accounting for movement, exercise, and the energy used to digest food [1]. Multiply your BMR by your activity factor:

Activity Level	Description	Multiplier
Sedentary	Office job, little exercise	× 1.2
Lightly Active	Light exercise 1–3 days/week	× 1.375
Moderately Active	Moderate exercise 3–5 days/week	× 1.55
Very Active	Hard exercise 6–7 days/week	× 1.725
Extra Active	Physical job + daily training	× 1.9

So for our example: 1,445 × 1.375 (lightly active) = 1,987 kcal/day TDEE. This is her maintenance — how much she needs to eat to stay at her current weight.

💡 Important: Most people overestimate their activity level. If you have a desk job and walk casually, you are sedentary (×1.2), not lightly active. Overestimating leads to eating too much and stalled weight loss [3].

Free Calorie Calculator

Use this calculator to find your personalised daily calorie target for weight loss:

🧮 TDEE & Calorie Deficit Calculator

Sex

Age (years)

Weight (kg)

Height (cm)

Activity Level

Goal

Your BMR—

Your TDEE (maintenance)—

Daily Calorie Target—

How Big Should Your Calorie Deficit Be?

Not all deficits are equal. The research consistently points to a moderate deficit of 300–500 kcal/day as the safest and most sustainable approach for most adults [4]:

Too small (under 200 kcal): Weight loss is extremely slow and easily wiped out by minor daily fluctuations in water retention.
Moderate (300–500 kcal): Produces 0.3–0.5 kg/week of fat loss. Muscle mass is preserved. Hunger is manageable. Adherence is high.
Too large (750+ kcal): Faster scale movement, but significantly more muscle loss, hormonal disruption, and risk of metabolic adaptation — your body slows its burn to compensate [5].

Calorie Deficit vs. Weekly Fat Loss Chart

Here's what different daily deficits look like in terms of weekly and monthly fat loss, based on the 7,700 kcal/kg fat calculation [6]:

📊 Daily Calorie Deficit → Projected Fat Loss

Theoretical projections based on 7,700 kcal/kg fat. Actual results vary due to water retention, metabolic adaptation, and adherence [6].

Real-World Examples

Profile	TDEE	Target Calories	Expected Loss
Woman, 30, 70kg, sedentary	1,733 kcal	1,233–1,483 kcal	0.3–0.5 kg/week
Man, 35, 85kg, lightly active	2,345 kcal	1,845–2,095 kcal	0.3–0.5 kg/week
Woman, 25, 60kg, moderately active	1,938 kcal	1,438–1,688 kcal	0.3–0.5 kg/week
Man, 40, 100kg, very active	3,105 kcal	2,605–2,855 kcal	0.3–0.5 kg/week

Person tracking calories and weight loss on scale

3 Common Calorie Mistakes That Stall Weight Loss

Underreporting portion sizes. A 2020 study found that people underestimate calorie intake by 30–50% on average [3]. Measure your food for 7 days — you will be surprised how much a "handful" actually weighs.
Not accounting for exercise calories burned. Many people eat back all of their exercise calories based on gym machine estimates, which overstate calorie burn by 25–40% [7]. Use your activity multiplier in TDEE instead of adding calories back.
Setting too aggressive a deficit and quitting. A 1,000 kcal daily deficit means extreme hunger, muscle loss, and fatigue. Studies consistently show that adherence drops sharply below 1,200 kcal in women and 1,500 kcal in men [4]. Slow and steady wins.

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References

Levine JA. (2004). Nonexercise activity thermogenesis (NEAT). Science, 307(5709), 584–586.
Frankenfield D, et al. (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults. Journal of the American Dietetic Association, 105(5), 775–789.
Dhurandhar NV, et al. (2015). Energy balance measurement: when something is not better than nothing. International Journal of Obesity, 39(7), 1109–1113.
Areta JL, et al. (2014). Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. Journal of Physiology, 591(9), 2319–2331.
Trexler ET, et al. (2014). Metabolic adaptation to weight loss: implications for the athlete. Journal of the International Society of Sports Nutrition, 11(1), 7.
Hall KD, et al. (2012). Quantification of the effect of energy imbalance on bodyweight. The Lancet, 378(9793), 826–837.
Drenowatz C & Eisenmann JC. (2011). Validation of the SenseWear Armband at high intensity exercise. European Journal of Applied Physiology, 111(5), 883–887.

How Many Calories to Lose Weight? (Science + Free Calculator)