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

1 kilogram of body fat is roughly equal to 7,700 calories. To lose about 0.5 kg to 1 kg per week safely, aim for a daily calorie deficit between 500 and 750 calories below your TDEE.

Is my health data saved or shared?

No. Our calculator runs completely in your local browser. No personal health information is ever uploaded or stored on any remote server.

Accurate BMI & Daily Calorie Calculator

Scientifically calculated with the Mifflin-St Jeor formula. Discover your ideal body weight, daily caloric burn, and personalized nutrition macro goals.

🔒 100% Client-Side Privacy: Your data never leaves your device.

Enter Your Details

Biological Gender

👨 Male

👩 Female

Age (Years)

Height (cm)

Weight (kg)

Daily Physical Activity

Your Body Metrics

Live Calculated

Your BMI Score 23.5 Normal Weight

18.5 25.0 30.0

🔥

BMR (At Rest) 1,680 kcal

🎯

Ideal Weight Range 57 - 76 kg

💧

Daily Water Intake 2.5 Liters

Daily Caloric Targets (TDEE)

Maintain Weight

Keep your current weight stable

2,310 kcal/day

Mild Weight Loss

0.25 kg / week (Gentle & Sustainable)

2,060 kcal/day

Fast Weight Loss

0.5 kg / week (-500 kcal deficit)

1,810 kcal/day

Weight / Muscle Gain

+0.5 kg / week (+500 kcal surplus)

2,810 kcal/day

Recommended Daily Macronutrients (Maintenance)

🍗 Protein (30%) 173g

🍚 Carbs (40%) 231g

🥑 Healthy Fats (30%) 77g

Understanding Your Body Mass Index (BMI)

Body Mass Index (BMI) is a standardized screening metric recognized by the World Health Organization (WHO) and the National Health Service (NHS). It categorizes an adult's weight in relation to their height to assess potential health risks associated with underweight, overweight, and obesity.

BMI Range	Category	Health Implication
< 18.5	Underweight	Higher risk of nutritional deficiency and osteoporosis.
18.5 – 24.9	Normal Weight	Optimal balance; lowest statistical risk for cardiovascular diseases.
25.0 – 29.9	Overweight	Slightly increased risk of hypertension and type-2 diabetes.
30.0 & Above	Obese	Elevated cardiovascular, joint, and metabolic risk factors.

How Are Calorie Requirements Calculated?

Our tool implements the Mifflin-St Jeor Equation, recognized by nutritional scientists as the most reliable formula for predicting Basal Metabolic Rate (BMR):

For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5

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

Once your resting metabolic rate is identified, it is multiplied by your physical activity multiplier to determine your TDEE (Total Daily Energy Expenditure). Creating a sustainable daily deficit of 500 kcal below your TDEE results in approximately 0.5 kg (1 lb) of fat loss per week without extreme starvation.

Frequently Asked Questions (FAQ)

What is the difference between BMR and TDEE?

Your BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep essential organs functioning (brain, heart, lungs). Your TDEE (Total Daily Energy Expenditure) accounts for both your BMR and the calories burned through daily physical activity, exercise, and digestion.

Why does BMI not differentiate between muscle and fat?

BMI relies strictly on height and total weight. Highly athletic individuals or bodybuilders with substantial muscle mass may register as "Overweight" on the BMI scale despite having very low body fat. While BMI is a reliable population guide, pairing it with body fat percentage provides a more complete health picture.

How many calories should I eat to lose weight safely?

A safe and medically recommended weight loss rate is 0.5 kg (1 lb) per week, achieved by maintaining a 500 kcal daily deficit below your TDEE. Health authorities caution against dropping below 1,200 calories per day for women or 1,500 calories for men without direct medical supervision.

Is my personal health data saved on your servers?

No. FitCalc operates 100% inside your local web browser using JavaScript. No names, ages, heights, or weights are ever sent to, recorded, or stored on any remote web server.