Want to take control of your diet and fitness? Our BMR & Calorie Calculator estimates your Basal Metabolic Rate (BMR) and daily calorie needs based on your age, weight, height, and activity level. Ideal for weight loss, muscle gain, or healthy living, this tool provides tailored insights to power your goals.
A BMR & Calorie Calculator calculates your Basal Metabolic Rate—the energy your body burns at rest to keep vital organs like the heart, lungs, and brain functioning. It then adjusts for activity to estimate your total daily calorie needs, offering:
BMR typically makes up ~70% of your daily calorie burn, with physical activity (~20%) and digestion (~10%, or thermogenesis) covering the rest. Accurate BMR requires a fully rested state, but our calculator delivers reliable estimates instantly.
The calculator uses the Mifflin-St Jeor equation to estimate BMR, then applies an activity factor (1.2–1.9) to calculate Total Daily Energy Expenditure (TDEE). It also supports advanced strategies like zigzag calorie cycling to boost metabolism.
Example:
Female, 28 years, 60 kg, 160 cm, lightly active
BMR: (10 × 60) + (6.25 × 160) - (5 × 28) - 161 = 1,299 kcal
TDEE (Light Activity, 1.4 factor): 1,299 × 1.4 ≈ 1,819 kcal
Mifflin-St Jeor Equation:
Men: BMR = 10W + 6.25H - 5A + 5
Women: BMR = 10W + 6.25H - 5A - 161
Revised Harris-Benedict Equation:
Men: BMR = 13.397W + 4.799H - 5.677A + 88.362
Women: BMR = 9.247W + 3.098H - 4.330A + 447.593
Katch-McArdle Formula:
BMR = 370 + 21.6(1 - F)W
Where: W = weight (kg), H = height (cm), A = age, F = body fat (%)
You’ll get:
✔ Your BMR and daily calorie needs
✔ Goal-specific calorie recommendations
✔ Tips for zigzag cycling and meal planning
Q1: How reliable are BMR calculations?
✅ Our calculator uses the Mifflin-St Jeor equation, the most accurate formula, though individual factors may cause slight variations.
Q2: What is zigzag calorie cycling?
✅ It alternates high and low calorie days to keep your metabolism active and avoid weight loss plateaus.
Q3: Does it account for body fat?
✅ Yes, the Katch-McArdle formula is ideal if you know your body fat percentage.
Q4: How does diet impact BMR?
✅ Frequent small meals can boost BMR, while starvation may reduce it by up to 30%.
Q5: Can I use imperial units?
✅ Yes, input weight in pounds and height in feet/inches.
Your Basal Metabolic Rate (BMR) is the energy your body needs at rest to maintain essential functions like breathing, heart rate, and organ activity. It’s the baseline for your daily calorie needs, typically making up ~70% of your total burn. The rest comes from physical activity (~20%) and digestion (~10%). Our calculator uses the Mifflin-St Jeor equation for accuracy, with options like the Katch-McArdle formula for those with known body fat percentages.
Zigzag calorie cycling alternates high and low calorie days to keep your metabolism guessing, preventing plateaus during weight loss. Example schedules:
Knowing the calorie content of foods helps you plan balanced meals:
| Food | Serving Size | Calories |
|---|---|---|
| Fruits | ||
| Apple | 1 (4 oz) | 59 |
| Banana | 1 (6 oz) | 151 |
| Strawberry | 1 cup | 53 |
| Vegetables | ||
| Broccoli | 1 cup | 45 |
| Carrot | 1 cup | 50 |
| Lettuce | 1 cup | 5 |
| Proteins | ||
| Chicken, cooked | 2 oz | 136 |
| Tofu | 4 oz | 86 |
| Egg | 1 large | 78 |
| Meals/Snacks | ||
| Pizza | 1 slice (14") | 285 |
| Sandwich (Turkey) | 6" sub | 200 |
| Beverages/Dairy | ||
| Milk (2%) | 1 cup | 122 |
| Orange Juice | 1 cup | 111 |
These meal plans align with different calorie goals:
| Meal | 1200 Cal Plan | 1500 Cal Plan | 2000 Cal Plan |
|---|---|---|---|
| Breakfast | All-bran cereal (125) Milk (50) Banana (90) | Granola (120) Greek yogurt (120) Blueberries (40) | Buttered toast (150) Egg (80) Banana (90) Almonds (170) |
| Snack | Cucumber (30) Avocado dip (50) | Orange (70) | Greek yogurt (120) Blueberries (40) |
| Total | 345 Calories | 350 Calories | 650 Calories |
| Lunch | Grilled cheese with tomato (300) Salad (50) | Chicken and vegetable soup (300) Bread (100) | Grilled chicken (225) Grilled vegetables (125) Pasta (185) |
| Snack | Walnuts (100) | Apple (75) Peanut butter (75) | Hummus (50) Baby carrots (35) Crackers (65) |
| Total | 450 Calories | 550 Calories | 685 Calories |
| Dinner | Grilled Chicken (200) Brussel sprouts (100) Quinoa (105) | Steak (375) Mashed potatoes (150) Asparagus (75) | Grilled salmon (225) Brown rice (175) Green beans (100) Walnuts (165) |
| Total | 405 Calories | 600 Calories | 665 Calories |
Physical activity significantly impacts calorie expenditure:
| Activity (1 hour) | 125 lb person | 155 lb person | 185 lb person |
|---|---|---|---|
| Walking (3.5 mph) | 215 | 267 | 319 |
| Kayaking | 283 | 352 | 420 |
| Swimming (moderate) | 397 | 492 | 587 |
| Running (9 min/mile) | 624 | 773 | 923 |
| Bicycling (12-14 mph) | 454 | 562 | 671 |
Different nutrients contribute varying amounts of energy:
| Nutrient | kcal/gram | kcal/ounce |
|---|---|---|
| Fat | 8.8 | 249 |
| Protein | 4.1 | 116 |
| Carbohydrate | 4.1 | 116 |
| Fiber | 1.9 | 54 |
| Alcohol | 6.9 | 196 |
While often used interchangeably, BMR measures energy use at complete rest, while RMR (Resting Metabolic Rate) captures energy in a relaxed state. BMR requires stricter conditions, making RMR easier to estimate in practice.
Research from 2005* shows a 26% unexplained variance in BMR, even after factoring in muscle mass and age. This means BMR and TDEE are estimates. Pair calculations with a food and exercise journal for personalized results.
* Johnstone AM, Murison SD, Duncan JS, Rance KA, Speakman JR, Factors influencing variation in basal metabolic rate. Am J Clin Nutr 2005; 82: 941-948.
Understanding your BMR and calorie needs is the foundation of effective weight management and fitness. Our Free BMR & Calorie Calculator delivers accurate estimates, meal plans, and strategies like zigzag cycling to keep you on track.
🚀 Start your nutrition journey today!
This content for the BMR & Calorie Calculator is independently researched and authored by me, drawing from nutritional science, metabolic research, and dietary planning principles.