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BMR Calculator

Find out exactly how many calories your body burns at rest. Enter your age, gender, height and weight below to calculate your Basal Metabolic Rate — then see your full daily calorie, macro and hydration breakdown in one shot.

✓ Free Forever ✓ Doctor-Grade Formulas ✓ Instant Results

Advanced BMR Calculator

Please enter valid age, height and weight to calculate your BMR.

Step 2

Your TDEE Estimate

TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. It tells you how many calories you actually burn in a full day, including movement and exercise.

Activity LevelMultiplierCalories/day
Sedentary little/no exercisex1.2--
Light 1-3 days/weekx1.375--
Moderate 3-5 days/weekx1.55--
Active 6-7 days/weekx1.725--
Athlete 2x/day trainingx1.9--

Fill the calculator above and hit Calculate BMR to see your personal TDEE numbers instead of the example above.

Step 3

Daily Calorie Recommendation

Once you know your TDEE, adjust it up or down depending on your goal. A safe, sustainable rate of change is 0.25-0.5 kg per week — faster than that usually costs you muscle, energy and consistency.

GoalDaily AdjustmentCalories/day
Lose 0.5 kg/week-500 kcal--
Lose 0.25 kg/week-250 kcal--
Maintain Weight0 kcal--
Gain 0.25 kg/week+250 kcal--
Gain 0.5 kg/week+500 kcal--
Step 4

Macronutrient Breakdown

Based on your maintenance calories, here's a balanced macro split — 30% protein, 40% carbs, 30% fat. Protein is set generously to protect muscle whether you're losing, maintaining or gaining.

Protein -- g 30%
Carbs -- g 40%
Fat -- g 30%
Step 5

Ideal Water Intake

A simple, widely-used estimate is 33 ml of water per kg of body weight per day. It's a starting point — heat, altitude and workout intensity all push this number higher.

-- litres/day

≈ -- glasses of 250 ml

The Science

Formula Used to Calculate BMR

This calculator defaults to the Mifflin-St Jeor equation — the formula most dietitians and clinicians consider the most accurate for the general population. Two older formulas are shown below for comparison.

Mifflin-St Jeor (Male)

BMR = 10 × Weight(kg) + 6.25 × Height(cm) − 5 × Age(yrs) + 5

Mifflin-St Jeor (Female)

BMR = 10 × Weight(kg) + 6.25 × Height(cm) − 5 × Age(yrs) − 161
FormulaBest ForNeeds Body Fat %
Mifflin-St JeorGeneral population, most accurate on averageNo
Harris-BenedictOlder formula (1919, revised 1984), slightly overestimatesNo
Katch-McArdleLean, athletic or muscular individualsYes

Harris-Benedict: Men = 88.36 + (13.4 × kg) + (4.8 × cm) − (5.7 × age)  |  Women = 447.6 + (9.2 × kg) + (3.1 × cm) − (4.3 × age)

Katch-McArdle: BMR = 370 + (21.6 × Lean Body Mass in kg), where Lean Body Mass = Weight × (1 − Body Fat%)

Worked Example

How We Calculate Your BMR

Here's a full walkthrough using a real example: a 30-year-old male, 70 kg, 175 cm tall.

1
Weight component: 10 × 70 kg = 700
2
Height component: 6.25 × 175 cm = 1093.75
3
Age component: 5 × 30 years = 150
4
Combine (male): 700 + 1093.75 − 150 + 5 = 1,648.75 ≈ 1,649 calories/day
5
TDEE at moderate activity: 1,649 × 1.55 ≈ 2,556 calories/day
Reference Data

Average BMR by Age

Approximate average BMR values by age group, calculated at average adult height and weight for each gender. Use this only as a rough reference — your own inputs above give a far more accurate number.

Male Female
20-29
30-39
40-49
50-59
60-69
70+
Beyond Rest

Calories Burned by Activity (30 min)

These are on top of your BMR — approximate for a 70 kg adult at moderate intensity.

🚶
Walking
150 cal
4-5 km/h pace
🏃
Running
330 cal
9-10 km/h pace
🚴
Cycling
260 cal
Moderate effort
🏊
Swimming
300 cal
Freestyle, steady
🏋
Gym / Weights
180 cal
General resistance
🧘
Yoga
120 cal
Gentle session
🤸
Hiking
280 cal
Moderate trail
⚽
Football
420 cal
Recreational play
Boost It

Tips to Increase Metabolism

Eat More Protein

Protein has the highest thermic effect of food — your body burns more calories digesting it than fat or carbs.

Prioritise Sleep

Poor sleep disrupts hunger hormones and can lower resting energy expenditure over time.

Strength Train

More muscle mass raises your BMR, since muscle burns more calories at rest than fat tissue.

Stay Hydrated

Even mild dehydration can measurably slow metabolic rate — water is involved in every energy-producing reaction.

Walk More Daily

Non-exercise movement (NEAT) can account for a large share of your total daily calorie burn.

Manage Stress

Chronic stress can affect hormones that influence metabolism, appetite, and long-term weight management.

Questions

Frequently Asked Questions

BMR (Basal Metabolic Rate) is the number of calories your body needs to perform basic life-sustaining functions — breathing, circulation, cell production — while completely at rest.
Formula-based BMR is an estimate, typically within 10% of your true value measured by indirect calorimetry in a lab. Mifflin-St Jeor is considered the most accurate equation for most people.
BMR is calories burned at complete rest. TDEE adds in calories burned through daily activity, exercise and digestion — it's always higher than BMR.
Start from your TDEE, then adjust: eat below it to lose weight, at it to maintain, and above it to gain. Use the Daily Calorie Recommendation section above for exact numbers.
Mifflin-St Jeor is generally regarded as the most accurate for the general population. Katch-McArdle is better if you know your body fat percentage and are lean or muscular.
Lower BMR is often linked to lower muscle mass, older age, being female, restrictive dieting history, or hormonal/thyroid factors. Strength training and adequate protein can help raise it over time.
Yes. BMR typically declines gradually with age, largely due to natural loss of muscle mass, unless it's actively maintained through resistance training.
Yes. Muscle tissue is metabolically active and burns more calories at rest than fat tissue, so more muscle mass generally means a higher BMR.
Yes. The default Mifflin-St Jeor and Harris-Benedict formulas only need age, gender, height and weight. Body fat percentage is only required for the Katch-McArdle formula.
They're closely related but not identical. RMR (Resting Metabolic Rate) is measured under slightly less strict conditions than BMR and is typically 5-10% higher, though the terms are often used interchangeably.
No. Eating at or below your BMR long-term isn't recommended — it can signal starvation-like conditions to your body. Base your intake on TDEE, not BMR alone.
Yes. Men typically have a higher BMR than women of the same age, height and weight, mainly because men tend to carry more lean muscle mass on average.
Recalculate whenever your weight changes by more than 2-3 kg, or every 4-6 weeks during an active weight loss or gain phase.
These formulas are designed and validated for adults. Children and teenagers have different metabolic patterns and should consult a pediatrician for growth-appropriate calorie guidance.
Yes, BMR rises during pregnancy to support fetal growth. Standard formulas don't account for this — pregnant individuals should follow guidance from their doctor rather than a general calculator.
A deficit of 250-500 calories per day below TDEE is considered sustainable, producing roughly 0.25-0.5 kg of weight loss per week without excessive muscle loss.
Different calculators may use different formulas (Mifflin-St Jeor vs Harris-Benedict vs Katch-McArdle), which naturally produce slightly different results. The gap is usually small — under 5-10%.
Yes. Fever, illness, and chronic stress can temporarily raise BMR, while conditions like hypothyroidism tend to lower it. If you suspect a medical cause, consult a doctor.
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