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

1 kg of body fat contains approximately 7,700 calories. To lose 1 kg per week, you need a daily calorie deficit of about 1,100 kcal (7,700 ÷ 7). This is aggressive for most people — a more sustainable target is 0.5 kg/week, requiring a 550 kcal/day deficit.

What is the difference between BMR and TDEE?

BMR is the calories your body burns at complete rest — what you would burn lying in bed all day without moving. TDEE adds the energy used by daily activities and exercise. TDEE is always higher than BMR, typically by 20–90% depending on activity level.

Should I eat back calories burned during exercise?

If you used the TDEE formula with an accurate activity multiplier, exercise energy expenditure is already factored in — do not add it back. If you used the sedentary multiplier and then exercise, eating back some (50–75%) of exercise calories is reasonable to avoid excessive restriction.

Why am I not losing weight even though I'm eating at a deficit?

Common reasons include: underestimating portion sizes (use a food scale), overestimating calories burned during exercise, water retention masking fat loss, or a TDEE estimate that is too high. Track consistently for 3–4 weeks before drawing conclusions.

Formula Guide

How to Calculate Your Daily Calorie Needs (TDEE)

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns each day, accounting for your metabolic rate at rest plus the energy used during physical activity. Knowing your TDEE lets you set a precise calorie target: eat at TDEE to maintain weight, below it to lose, or above it to gain muscle. The Mifflin-St Jeor equation is the formula most widely validated in research for estimating TDEE.

Last updated: March 31, 2026

The Formula

Step 1 — BMR (Basal Metabolic Rate):
  Men:   BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5
  Women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161

Step 2 — TDEE:
  TDEE = BMR × Activity Multiplier

Activity multipliers: Sedentary (1.2), Lightly active 1–3 days/week (1.375), Moderately active 3–5 days/week (1.55), Very active 6–7 days/week (1.725), Athlete/physical job (1.9).

Variable Definitions

Symbol	Name	Description
BMR	Basal Metabolic Rate	Calories burned at complete rest — the energy required to keep your organs functioning
weight	Body Weight	Current weight in kilograms
height	Height	Height in centimetres
age	Age	Age in years
Activity Multiplier	Activity Factor	A value from 1.2 to 1.9 based on how active you are during a typical week

Step-by-Step Example

A 35-year-old woman weighing 68 kg, 165 cm tall, who exercises moderately 4 times a week. What is her TDEE and her calorie target to lose 0.5 kg/week?

Given

Weight:68 kgHeight:165 cmAge:35Activity level:Moderately active (×1.55)

Solution

1
Calculate BMR (women's formula): 10×68 + 6.25×165 − 5×35 − 161
2
Expand the equation: 680 + 1031.25 − 175 − 161 = 1375 kcal
3
Multiply by activity factor for TDEE: 1375 × 1.55 = 2131 kcal/day
4
Subtract 500 kcal for ~0.5 kg/week loss: 2131 − 500 = 1631 kcal/day target

TDEE is 2,131 kcal/day. To lose approximately 0.5 kg per week, eat around 1,631 kcal/day.

Ready to calculate?

Use the free Calorie Calculator — instant results, no sign-up.

Open Calculator

Common Mistakes to Avoid

Using the wrong formula — the male and female formulas differ by the final constant (+5 vs −161). Make sure you apply the right one.

Using pounds instead of kilograms or inches instead of centimetres — the Mifflin-St Jeor formula requires metric units.

Overestimating activity level — most people are 'lightly active' or 'sedentary', not 'very active'. Honest activity assessment is the biggest source of error.

Treating TDEE as exact — it is an estimate with a margin of ±200–300 kcal/day. Track actual weight changes over 2–3 weeks and adjust accordingly.

Frequently Asked Questions

Related Guides

How to Calculate BMI

BMI Calculator

How to Calculate Body Fat Percentage (Navy Method)

Body Fat % Calculator

How to Calculate Your Macros

Macro Calculator