What is the Cunningham formula?

The Cunningham formula calculates Resting Metabolic Rate as RMR = 500 + (22 x lean body mass in kg). It was developed specifically for athletes and outperforms other formulas when muscle mass is above average.

How is Cunningham different from Katch-McArdle?

Both formulas use lean body mass. Katch-McArdle uses BMR = 370 + (21.6 x LBM), while Cunningham uses RMR = 500 + (22 x LBM). Cunningham tends to give slightly higher estimates and was validated on athletic populations.

What is lean body mass?

Lean body mass (LBM) is total body weight minus fat mass — it includes muscle, bone, organs, and water. LBM = weight x (1 - body fat% / 100).

How do I find my body fat percentage?

DEXA scan and hydrostatic weighing are the most accurate. InBody devices, skinfold calipers, and online measurement-based calculators are widely available alternatives with lower precision.

What activity multiplier should I use?

Sedentary (desk job, no exercise) = 1.2. Lightly active (1-3 days/week) = 1.375. Moderately active (3-5 days/week) = 1.55. Very active (6-7 days/week) = 1.725. Extra active (physical job + hard daily training) = 1.9.

Is RMR the same as BMR?

They are nearly identical in practice. BMR (Basal Metabolic Rate) is measured under strict lab conditions (complete rest, fasted). RMR (Resting Metabolic Rate) is measured at rest but without strict fasting protocols. RMR is typically 10-20% higher than BMR.

Cunningham BMR Calculator

Name: Cunningham BMR Calculator
Availability: InStock
Author: Nham Vu

Enter your weight and body fat percentage to calculate RMR using the Cunningham formula (RMR = 500 + 22 x LBM), ideal for athletes with higher muscle mass.

Your Measurements

Body Weight (kg)

Body Fat Percentage (%)

Not sure? Use a body fat estimation tool first.

Lean Body Mass 68.0 kg

Activity Level

Enter your details and click Calculate to see your results.

Cunningham RMR

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kcal / day at rest

TDEE

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kcal / day (active)

Body Composition

Total Weight

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Fat Mass

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Lean Mass

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FatLean

15% 85%

Calorie Targets

Aggressive cut (-1000 kcal) —

Moderate cut (-500 kcal) —

Maintenance —

Lean bulk (+250 kcal) —

Aggressive bulk (+500 kcal) —

Cunningham Formula: RMR = 500 + (22 × LBM_kg) • TDEE = RMR × activity multiplier

Summary