Leangains Calculator

Reviewed by: David Chen, CSCS (Certified Strength and Conditioning Specialist)

Optimize your intermittent fasting and macronutrient cycling with our precision Leangains Calculator. Designed for the 16/8 protocol to help you master body recomposition.

Leangains Calculator

Scroll down or check “Steps” for macro splits.

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Leangains Calculator Formula

BMR (Mifflin-St Jeor):
Male: 10W + 6.25H – 5A + 5
Female: 10W + 6.25H – 5A – 161
TDEE = BMR × Activity Multiplier
Leangains Split: TDEE cycling based on training schedule.

Formula references and methodology sourced from Leangains Official and the National Institutes of Health (NIH) regarding the Mifflin-St Jeor equation.

Variables Explained:

• Weight (W): Your current body weight in kilograms.
• Height (H): Your height in centimeters.
• Age (A): Your biological age.
• Activity Level: Your TDEE multiplier based on exercise frequency.
• Goal: Defines the calorie surplus/deficit split between training and rest days.

Related Calculators

• → Macro Cycling Calculator
• → Intermittent Fasting Timer
• → Body Recomposition Tool
• → TDEE Adjuster for Athletes

What is the Leangains Calculator?

The Leangains calculator is a specialized tool designed to implement the training and nutrition principles developed by Martin Berkhan. Unlike standard calorie calculators, it focuses on calorie and carb cycling in conjunction with an 16:8 intermittent fasting window.

The core philosophy is to eat more calories and carbohydrates on training days (to fuel growth) and fewer calories with higher fats on rest days (to encourage fat oxidation). This “recomposition” approach aims to build muscle while losing fat simultaneously.

How to Calculate Leangains Split (Example)

1. Find your TDEE (e.g., 2500 kcal).
2. For a Recomp (+20% / -20%):
3. Training Day: 2500 + 500 = 3000 kcal.
4. Rest Day: 2500 – 500 = 2000 kcal.
5. Set protein at ~2.5g per kg of body weight for both days.

Frequently Asked Questions (FAQ)

Is Leangains better for cutting or bulking?

It is specifically optimized for “clean bulking” and “body recomposition,” allowing for lean muscle gains without significant fat accumulation.

What is the 16/8 window?

It means fasting for 16 hours (usually including sleep) and consuming all calories within an 8-hour window, typically starting around noon.

Why cycle carbohydrates?

Carbohydrates are insulinogenic. By consuming them mostly on training days, you shuttle nutrients into muscles when they are most insulin-sensitive.

Should I use kg or lbs?

This calculator uses kg/cm for scientific accuracy. 1kg = 2.2lbs, and 1 inch = 2.54cm.