This **Katch-McArdle calculator** is an **advanced tool** designed to estimate your **Basal Metabolic Rate (BMR)** with **greater precision** than traditional methods using Katch-McArdle equation.

The calculator was developed by researchers **Frank Katch** and **William McArdle** to provide a more **accurate assessment** of daily energy expenditure.

Unlike simpler calculators that only consider **weight**, **height**, **age**, and **gender**, the Katch-McArdle formula incorporates **lean body mass (LBM)** as its primary variable, making it particularly valuable for **athletes** and **fitness enthusiasts**.

## Katch-McArdle Calculator

Weight (lbs) | Body Fat % | LBM (kg) | BMR (calories) | Activity Level | TDEE (calories) |
---|---|---|---|---|---|

150 | 15% | 57.8 | 1,618 | Moderate | 2,508 |

180 | 20% | 65.3 | 1,780 | Light | 2,448 |

200 | 25% | 68.0 | 1,839 | Very Active | 3,172 |

165 | 18% | 61.4 | 1,696 | Sedentary | 2,035 |

140 | 12% | 61.9 | 1,635 | Moderate | 2,455 |

175 | 22% | 68.5 | 1,795 | Light | 2,473 |

220 | 30% | 154.0 | 2,020 | Very Active | 3,471 |

160 | 25% | 120.0 | 1,740 | Moderate | 2,697 |

190 | 28% | 136.8 | 1,855 | Light | 2,545 |

210 | 24% | 159.6 | 2,032 | Very Active | 3,470 |

130 | 10% | 117.0 | 1,570 | Sedentary | 1,884 |

155 | 20% | 124.0 | 1,715 | Moderate | 2,636 |

185 | 27% | 135.5 | 1,850 | Light | 2,586 |

230 | 32% | 156.0 | 2,090 | Extremely Active | 3,951 |

## Katch-McArdle Formula

The **Katch-McArdle equation** is expressed as:

**BMR = 370 + (21.6 × Lean Body Mass in kg)**

**Lean Body Mass (LBM)** is calculated as:

**Lean Body Mass = Weight × ((100 - Body Fat Percentage) / 100)**

**BMR Calculation**: Once lean body mass is known, the **Katch-McArdle equation** for BMR is:

**BMR = 370 + (21.6 × Lean Body Mass in kg)**

For instance, let’s calculate the BMR for a person with:

- Total weight: 170 lbs (77.1 kg)
- Body fat percentage: 20%

First, calculate lean body mass:

- LBM = 170 lbs × (1 – 0.20) = 136 lbs
- Convert to kg: 136 lbs × 0.454 = 61.7 kg

Then apply the formula: BMR = 370 + (21.6 × 61.7) =

1,703 calories per day

## How to Calculate the Katch McArdle Formula?

To accurately calculate using the Katch-McArdle formula, follow these detailed steps:

**Measure Body Fat Percentage**, Use calipers, DEXA scan, Hydrostatic weighing, Bioelectrical impedance**Calculate Lean Body Mass**: Total Weight × (1 – Body Fat Percentage)**Convert to Metric**: Pounds to Kilograms (multiply by 0.454)**Apply the Formula**: Input converted LBM into the equation**Calculate Total Daily Energy Expenditure (TDEE)**- Multiply BMR by activity factor:
- Sedentary: × 1.2
- Light Activity: × 1.375
- Moderate Activity: × 1.55
- Very Active: × 1.725
- Extremely Active: × 1.9

- Multiply BMR by activity factor:

## Is Katch McArdle Accurate?

The **Katch-McArdle formula** is considered more accurate than other BMR formulas because it accounts for body composition.

*Its accuracy depends on:*

**Precise Body Fat Measurements**: The formula’s accuracy is directly tied to how accurately you can measure body fat percentage.

**Individual Variations**: Genetic factors, Hormonal balance, Medical conditions

**Activity Level Assessment**: Accurate selection of activity multiplier.

Research suggests it’s particularly accurate for:

**Athletes****Bodybuilders**- Individuals with higher muscle mass
- People who regularly track their nutrition

## References

- American Council on Exercise (ACE) – “https://www.acefitness.org/resources/pros/expert-articles/5008/resting-metabolic-rate-how-to-calculate-and-improve-yours/“

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