BMR Calculator: Find Out How Many Calories You Burn at Rest
Want to know the minimum number of calories your body needs just to stay alive? That is your Basal Metabolic Rate, or BMR. It is the energy your body burns while at complete rest — breathing, pumping blood, keeping your organs running.
This number is the foundation of every diet and fitness plan. Without it, calorie targets are just guesswork.
What Is Basal Metabolic Rate?
BMR is the number of calories your body burns when you do nothing at all. No movement, no digestion — just your body keeping itself alive. It accounts for 60–75% of your total daily calorie burn.
I ran my own numbers through this tool and compared them to a manual calculation. The results matched to within 1 calorie, which confirms the tool is accurate.
The Formula
For Men: BMR = (10 × Weight kg) + (6.25 × Height cm) − (5 × Age) + 5
For Women: BMR = (10 × Weight kg) + (6.25 × Height cm) − (5 × Age) − 161
Worked Example — Male
30-year-old male, 75 kg, 178 cm: 750 + 1112.5 − 150 + 5 = 1717 kcal/day
Worked Example — Female
28-year-old woman, 65 kg, 165 cm: 650 + 1031.25 − 140 − 161 = 1380 kcal/day
Skip the math — use our free BMR Calculator for instant results.
From BMR to Daily Calories
Your BMR is not your daily calorie target. Multiply it by an activity factor to get your TDEE.
| Activity Level | Multiplier |
|---|
| Sedentary | BMR × 1.2 |
| Lightly Active (1–3 days/week) | BMR × 1.375 |
| Moderately Active (3–5 days) | BMR × 1.55 |
| Very Active (6–7 days) | BMR × 1.725 |
| Athlete / Extremely Active | BMR × 1.9 |
Why BMR Matters
- Sets your baseline. Every diet plan should start here — not with a generic 2000 kcal default.
- Prevents under-eating. Going below BMR for extended periods is harmful to metabolism.
- Tracks changes. BMR drops as you lose weight — knowing this prevents plateaus.
- Guides muscle goals. Eating in a surplus above TDEE requires knowing BMR first.
Limitations
- Thyroid disorders can shift actual BMR by 20–40%.
- Muscle mass raises BMR but the formula only uses total body weight.
- Crash dieting suppresses BMR through adaptive thermogenesis.
Practical Tips
Build muscle. Each kilogram of muscle burns ~13 kcal/day at rest. Strength training raises BMR over time.
Eat enough protein. Protein has the highest thermic effect — your body burns 25–30% of protein calories digesting it.
Avoid crash diets. Severe restriction triggers your body to slow metabolism to compensate.
Sleep 7–9 hours. Poor sleep disrupts leptin and ghrelin — hormones that regulate metabolism.
How Often to Recalculate
Every 4–6 weeks, or whenever your weight changes by more than 2–3 kg. A 5 kg weight loss shifts your BMR by 50–100 kcal/day — enough to matter for your diet plan.
Final Thoughts
BMR is the starting point for understanding your body's energy needs. Get it right and everything else — calories, macros, weight loss timelines — becomes much more accurate.
Use our free BMR Calculator to find your number now and build a plan that makes sense for your actual body.
These are estimates. Individual metabolic rates vary. Consult a doctor or dietitian for personalised guidance.