Leangains Calculator

Calculate your daily calories and macronutrients based on the Leangains methodology for optimal fat loss and muscle gain.

What is a leangains calculator?

A leangains calculator is a specialized tool designed to estimate your daily caloric and macronutrient needs based on the principles of the Leangains intermittent fasting protocol, created by Martin Berkhan. This method is not just about fasting; it involves a sophisticated approach to nutrition called “calorie cycling” and “macro cycling.” Essentially, you eat more calories and carbohydrates on training days to fuel performance and recovery, and fewer calories with higher fat content on rest days to promote fat loss.

Unlike a generic TDEE or macro calculator, a leangains calculator specifically computes two different sets of targets: one for your workout days and one for your rest days. The goal is to maximize muscle growth and repair while simultaneously stripping away body fat, a process often referred to as body recomposition. This calculator uses your personal data—age, gender, weight, height, and activity level—to first determine your baseline energy needs (BMR and TDEE) and then applies the Leangains-specific adjustments based on your fitness goal, whether it’s aggressive fat loss (cutting), muscle gain (lean bulking), or doing both at once (recomp).

The leangains calculator Formula and Explanation

The core of the leangains calculator involves a three-step process to get from your basic stats to your final, cycled macros. It’s a logical progression from your resting metabolism to your daily targets.

Step 1: Basal Metabolic Rate (BMR)

First, we calculate your BMR using the widely accepted Mifflin-St Jeor formula, which estimates the calories your body burns at complete rest.

BMR = 10 * weight (kg) + 6.25 * height (cm) - 5 * age (y) + s

The ‘s’ is a gender-specific variable: +5 for males and -161 for females.

Step 2: Total Daily Energy Expenditure (TDEE)

Next, we account for your daily activity. Your BMR is multiplied by an activity factor to determine your TDEE—your total daily calorie maintenance level.

TDEE = BMR * Activity Multiplier

The multipliers are standardized values that represent different lifestyles.

Step 3: Goal-Based Calorie & Macro Cycling

This is where the Leangains magic happens. Your TDEE is adjusted based on your goal (cut, recomp, bulk) for both training and rest days. Protein is generally kept high across all days, while carbohydrates and fats are cycled.

• Training Days: Higher calories and carbohydrates to fuel workouts and replenish glycogen.
• Rest Days: Lower calories and carbohydrates (and higher fat) to encourage fat burning.

Formula Variables

Variable	Meaning	Unit	Typical Range
Weight	Your body weight	kg or lbs	40 – 150 kg
Height	Your height	cm or in	140 – 220 cm
Age	Your current age	Years	18 – 80
Activity Multiplier	Factor representing daily physical activity	Unitless	1.2 – 1.9
Goal Modifier	Percentage adjustment for calories	%	-20% to +30%

For more on calculating your energy needs, see this TDEE calculator.

Practical Examples

Example 1: Male Aiming for Fat Loss (Cut)

John is a 35-year-old male, weighs 90 kg (198 lbs), is 185 cm tall, and is lightly active. He wants to cut fat.

• Inputs: Male, 35, 90kg, 185cm, Lightly Active, Cut goal.
• BMR Calculation: (10*90) + (6.25*185) – (5*35) + 5 = 1883 kcal.
• TDEE Calculation: 1883 * 1.375 = 2589 kcal.
• Results:
  • Training Day (TDEE +0%): ~2589 kcal. High Protein, High Carb, Low Fat.
  • Rest Day (TDEE -20%): ~2071 kcal. High Protein, Low Carb, High Fat.

Example 2: Female Aiming for Body Recomposition

Sarah is a 28-year-old female, weighs 60 kg (132 lbs), is 165 cm tall, and is moderately active. She wants to build muscle and lose fat simultaneously.

• Inputs: Female, 28, 60kg, 165cm, Moderately Active, Recomp goal.
• BMR Calculation: (10*60) + (6.25*165) – (5*28) – 161 = 1330 kcal.
• TDEE Calculation: 1330 * 1.55 = 2062 kcal.
• Results:
  • Training Day (TDEE +20%): ~2474 kcal. High Protein, High Carb, Low Fat.
  • Rest Day (TDEE -20%): ~1650 kcal. High Protein, Low Carb, High Fat.

To understand the difference between these goals, read about cutting vs bulking.

How to Use This leangains calculator

1. Select Your Units: Start by choosing between Metric (kg, cm) or Imperial (lbs, in) units. The labels will update automatically.
2. Enter Personal Details: Input your gender, age, weight, and height. Be as accurate as possible.
3. Choose Activity Level: Select the option that best describes your daily life, excluding your planned workouts. This is a common point of error; the calculation already assumes you are training.
4. Set Your Goal: Pick from Fat Loss (Cut), Body Recomposition, or Lean Bulk. The percentages next to the goals show the approximate calorie adjustments for your rest/training days relative to your TDEE.
5. Review Your Results: The calculator will instantly display your BMR, maintenance TDEE, and the specific calorie and macro targets for your rest and training days.
6. Interpret the Charts: The pie charts provide a visual breakdown of where your calories are coming from on each type of day, helping you understand the macro cycling concept.

Key Factors That Affect Leangains Results

• Diet Adherence: Consistency is king. Hitting your calorie and macro targets, especially protein, is the most critical factor.
• Training Intensity: Leangains is designed to be paired with heavy, progressive resistance training, typically using a Reverse Pyramid Training style. Without the right training stimulus, the nutrition protocol is less effective.
• Protein Intake: Leangains emphasizes a very high protein intake (around 2.5-3.0g per kg of bodyweight) to preserve muscle mass while dieting and support growth during a surplus. Understanding what macros are is crucial.
• Sleep Quality: Adequate sleep (7-9 hours) is essential for hormone regulation, muscle recovery, and managing hunger. Poor sleep can sabotage your efforts.
• Accurate Activity Estimation: Overestimating your TDEE is a common mistake that can lead to slow or no fat loss. When in doubt, choose a lower activity multiplier.
• Patience and Adjustment: Your initial calculation is a starting point. You must track your body weight and visual progress for 2-4 weeks and adjust your calorie intake up or down based on the results.

Frequently Asked Questions (FAQ)

1. Do I have to fast for 16 hours?

Yes, the 16-hour daily fast is a core principle of Leangains. It helps improve insulin sensitivity and makes it easier to adhere to a calorie deficit by allowing for larger, more satisfying meals in your 8-hour eating window.

2. What can I consume during the fast?

You can have zero-calorie beverages like black coffee, tea, and water. A splash of milk in coffee or sugar-free gum is generally considered acceptable and won’t break the fast.

3. Why are carbs and fats cycled?

Carbohydrates are the body’s primary fuel source for high-intensity exercise. By timing high-carb intake on training days, you maximize performance and recovery. On rest days, with lower energy demands, carbs are reduced and fat is increased to promote fat utilization and improve metabolic flexibility.

4. How accurate is this leangains calculator?

This calculator provides a highly educated estimate based on proven formulas. However, it’s just a starting point. Individual metabolic rates can vary. The best approach is to use these numbers for 2-3 weeks, track your progress, and make small adjustments as needed. A good tool for this might be an intermittent fasting calculator.

5. Do I need to train fasted?

While Martin Berkhan provides protocols for both fasted and fed training, many followers train in a fasted state (often after consuming 10g of BCAAs or EAAs) to potentially enhance fat mobilization.

6. Why is protein so high?

High protein intake is crucial for preserving lean muscle mass, especially when in a calorie deficit. It also has a high thermic effect of food (TEF) and is very satiating, which helps control hunger.

7. What if I train more or less than 3 days a week?

The Leangains protocol is optimized for 3-4 heavy resistance training sessions per week. If your schedule differs, simply apply the “Training Day” macros on days you lift and “Rest Day” macros on all other days.

8. Can I do Leangains if I’m a vegan?

Yes, but it can be more challenging to hit the high protein targets. You’ll need to rely heavily on high-protein vegan sources like tofu, tempeh, seitan, lentils, and quality vegan protein powders.

Related Tools and Internal Resources

Expand your knowledge and find tools to help you on your fitness journey.

• The Complete Intermittent Fasting Guide: Learn about the science and different methods of intermittent fasting.
• Body Recomposition Explained: A deep dive into how you can build muscle and lose fat at the same time.
• Macro Calculator: A general tool for calculating your macronutrient needs for various dietary approaches.
• TDEE Calculator: Find your total daily energy expenditure with our detailed TDEE calculator.
• Guide to Setting Fitness Goals: Learn how to set realistic and achievable goals for your fitness journey.
• Bulking vs. Cutting Strategies: Understand the pros and cons of focusing on one goal at a time.