Calorie Calculator (BMR & TDEE) — Free Online Tool

What Is Calorie Calculator (BMR & TDEE)?

A free online calorie calculator using the Mifflin-St Jeor formula. Calculate your Basal Metabolic Rate (BMR), Total Daily Energy Expenditure (TDEE), BMI, healthy weight range, and recommended macronutrient split. Supports weight loss, maintenance, and muscle gain goals.

Understanding your daily calorie needs is the foundation of effective weight management, whether your goal is weight loss, maintenance, or muscle gain. Calorie Calculator uses the Mifflin-St Jeor equation — one of the most accurate BMR formulas — to calculate your Basal Metabolic Rate, Total Daily Energy Expenditure, and recommended calorie intake for your specific goal.

Enter your age, gender, height, and weight. Select your activity level from six options: sedentary (little or no exercise), lightly active (1-3 days/week), moderately active (3-5 days/week), very active (6-7 days/week), extremely active (twice daily), or professional athlete. Each activity level applies a multiplier to your BMR to estimate your TDEE — the total calories your body burns per day.

Select your goal: lose weight (creates a calorie deficit of approximately 500 calories/day for about 1 lb/week loss), maintain weight (matches your TDEE exactly), or gain muscle (creates a surplus of approximately 300-500 calories/day). The calculator shows your goal calorie target alongside your BMR and TDEE.

The macronutrient breakdown recommends grams of protein, carbohydrates, and fat based on your goal calories. Standard recommendations: protein 25-30% (for muscle preservation), carbs 45-55% (for energy), and fat 20-30% (for hormone function). BMI calculation and healthy weight range are also displayed for additional context.

Real-World Use Cases for Calorie Calculator (BMR & TDEE)

Calculating Calories for Weight Loss

A 35-year-old woman weighing 170 lbs, 5'6", moderately active, wants to lose weight. Her BMR is ~1,500, TDEE is ~2,300, and goal calories are ~1,800/day. The macro split shows ~135g protein, ~225g carbs, ~45g fat. She uses this as a starting point and adjusts based on weekly progress.

Determining Maintenance Calories After Weight Loss

After losing 20 lbs, a man wants to maintain. He re-enters his current weight: 180 lbs, 5'10", lightly active. His TDEE is ~2,500 calories. He sets goal to "Maintain" and gets ~2,500 calories/day. He tracks his weight weekly and adjusts by 100-200 calories if needed.

Setting Up a Muscle Gain Diet Plan

A 25-year-old man, 160 lbs, 5'9", exercises 5 days/week, wants to gain muscle. Select "Gain Muscle" goal. His TDEE is ~2,800, goal calories ~3,200. Macro split: ~200g protein, ~400g carbs, ~70g fat. He focuses on hitting the protein target daily and eating slightly above maintenance.

Why Use Calorie Calculator (BMR & TDEE)?

Mifflin-St Jeor formula for accurate BMR
6 activity levels from sedentary to pro athlete
Weight loss, maintenance, and muscle gain goals
BMI calculation with healthy weight range

How to Use Calorie Calculator (BMR & TDEE) — Step by Step

Enter your age, gender, height, and weight.

Select your activity level (sedentary to pro athlete).

Choose your goal (lose weight, maintain, or gain muscle).

View your BMR, TDEE, goal calories, and macro split.

Who Is Calorie Calculator (BMR & TDEE) Best For?

fitness enthusiasts
diet planning
weight management
health tracking

Pro Tips for Calorie Calculator (BMR & TDEE)

1The Mifflin-St Jeor formula is accurate for the general population but individual metabolism varies. Use the calculated values as a starting point and adjust by 100-200 calories based on your actual rate of weight change.
2Activity level is the most subjective input. Most people overestimate their activity. If you are unsure, choose the lower activity level and adjust up if you lose weight too quickly.
3For weight loss, a deficit of 300-500 calories/day leads to sustainable 0.5-1 lb/week loss. Larger deficits can cause muscle loss, metabolic slowdown, and are harder to maintain.
4Protein intake is critical during both weight loss and muscle gain. Aim for at least 0.8g per lb of body weight when losing weight, and 1.0-1.2g per lb when gaining muscle.

Calorie Calculator (BMR & TDEE) — Frequently Asked Questions

What formula does this use?

This calculator uses the Mifflin-St Jeor equation, which is considered one of the most accurate BMR formulas for the general population.

What is the difference between BMR and TDEE?

BMR is the calories your body burns at complete rest. TDEE includes your activity level and represents your total daily calorie needs.

How accurate are the calculations?

All calculations use double-precision floating-point arithmetic following IEEE 754 standards. Financial calculations like loans and compound interest are verified against standard spreadsheet formulas.

Can I round results to a specific number of decimal places?

Results are typically displayed with up to 10 significant digits. You can mentally round to your desired precision for most practical use cases.

Is Calorie Calculator (BMR & TDEE) really free to use?

Yes, Calorie Calculator (BMR & TDEE) is completely free with no hidden charges, no usage limits, and no premium tiers. You can use it as often as you need without signing up or providing any personal information.

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