Basal Metabolic Rate (BMR) Calculator

Mifflin-St Jeor estimate

Your basal metabolic rate (BMR)

—kcal / day at rest

Estimated maintenance— kcal / day

GoalMaintenance— kcal0 %

Physical activity level (PAL): × —
Maintenance calculation: BMR × PAL

Theoretical estimate

How many days for 1 kg of body fat?

Average daily deficitkcal

26theoretical days

1 kg of adipose tissue ≈ 7,700 kcal. This calculation gives a rough estimate, not a guaranteed date on the scale.

Daily energy expenditure

Basal metabolic rate is only the foundation.

Your total expenditure combines four components. Their contribution varies with your body, diet, and daily routine.

Daily energy-expenditure pyramid showing basal metabolic rate (BMR), non-exercise activity thermogenesis (NEAT), exercise activity thermogenesis (EAT), and the thermic effect of food (TEF)

Basal metabolic rate (BMR): The energy your body needs at rest for breathing, circulation, temperature regulation, and organ function.
Non-exercise activity thermogenesis (NEAT): Walking, commuting, standing, daily tasks, and every movement outside a structured workout.
Exercise activity thermogenesis (EAT): Energy expended during structured physical activity such as strength training, running, cycling, or sport.
Thermic effect of food (TEF): Energy used to digest, absorb, transport, and store the nutrients you consume.

This decomposition follows the literature on total energy expenditure. James A. Levine The Pyramid is an educational representation of ShapeVision, not a model attributed to a single author.

Practical levers

What you can realistically change.

01 · NEAT

Increase your steps gradually.

Each week, add 1,000 to 2,000 steps to your daily average until you reach a level you can sustain.

6,000 extra steps per day≈ 60 min of walking · ≈ 210 active kcal at your entered weight

02 · EAT

Train as long as you can recover.

Cardio and strength training increase exercise expenditure, but not indefinitely. If fatigue rises, performance falls, or you move less during the rest of the day, adding more can become counterproductive.

03 · BMR & TEF

Do not look for a magic switch.

BMR depends mainly on your height, weight, age, and lean mass. TEF varies with food quantity and composition, but remains a secondary lever compared with NEAT and a recoverable amount of EAT.

From basal metabolic rate to your goal.

The Mifflin-St Jeor equation estimates resting energy expenditure from age, height, and weight. It is among the most reliable equations commonly used for adults.

Sources: Mifflin-St Jeor equation · comparative review

The activity coefficient starts from a sedentary baseline and then combines your step range, cardio sessions, and strength-training sessions. Step ranges are refined into smaller increments to keep the setting easy to use up to 25,000 steps. This method provides a more coherent estimate than a simple “low” or “high” choice, but it does not directly measure your energy expenditure.

Step ranges: Tudor-Locke and Bassett categories

For the walking estimate, 6,000 steps correspond to about one hour at 100 steps per minute. Active calories use moderate walking at an intensity of 3.8 metabolic equivalents (MET) after subtracting resting expenditure. Terrain, pace, and stride length can change the result.

Sources: walking cadence · Compendium of Physical Activities

The selected goal applies a moderate 10% deficit, no adjustment, or a slight 5% surplus. The 7,700 kcal-per-kilogram estimate is used only to calculate a theoretical duration: energy-expenditure adaptation slows actual weight loss, and more exercise does not always produce a proportional rise in total expenditure.

Sources: composition of weight loss · dynamic models · exercise-related compensation

How do you find your true maintenance in 14 days?

Eat near estimate.Keep a fairly regular intake for two weeks.
Follow an average.Be in similar conditions and compare weekly averages.
Adjust gradually.Add or remove 100 to 150 kcal if the trend does not match your goal.

To build protein intake around this total, use the guide how much protein per day.

Frequently asked questions

Which formula does the calculator use?

The calculator uses the Mifflin-St Jeor equation to estimate the energy expenditure at rest, used here as an approximation of the basic metabolism.

Does basic metabolism correspond to calories to eat?

No. Basic metabolism covers energy spent at rest. Maintenance adds daily activity, training and the thermal effect of food before applying your goal.

How is activity level estimated?

The calculator combines a sedentary baseline with your step range, 30-minute cardio sessions, and strength-training sessions. It still needs to be calibrated against your actual weight trend over 14 days.

Does a 7,700 kcal deficit always produce 1 kg of weight loss?

No. 7,700 kcal per kilogram is a theoretical estimate based on the energy stored in adipose tissue. Water, lean mass, appetite, and energy-expenditure adaptation make actual weight loss less linear.

Why can my weight vary at constant calories?

Water, glycogen, salt, and digestive content can shift weight from day to day. Rather, compares the two-week averages taken under similar conditions.

When should the estimate be adjusted?

After 14 days fairly regular. If the trend does not match your goal, change the intake from 100 to 150 kcal per day, then observe a new period.

In the app

Move from a calorie estimate to structured training.

Generate your program, log your workouts, and track your progress in ShapeVision.

Download on the App Store