Mifflin-St Jeor equation
The Mifflin-St Jeor equation is a 1990 formula widely adopted by dietitians. For example, a 70 kg male at 175 cm and 30 years old yields roughly 1,662 kcal. It anchors modern meal plans because it reflects contemporary body compositions more accurately than older models.
Revised Harris-Benedict
The revised Harris-Benedict equation updates a 1919 model with 1980s data. A 65 kg female at 165 cm and 40 years old returns about 1,360 kcal. Comparing it with Mifflin helps you bracket a realistic BMR corridor, especially for older adults.
Basal metabolic rate
Basal metabolic rate describes calories burned to sustain vital functions at complete rest. Knowing BMR clarifies the minimum energy your body needs before exercise or work is considered. Eating below this number for long periods is generally not recommended.
Resting energy expenditure
Resting energy expenditure is often used interchangeably with BMR in practical settings. The calculator treats them similarly, recognising minor measurement differences in clinical labs.
Energy per kilogram
Energy per kilogram divides average BMR by body weight. A reading of 21 kcal/kg signals efficient metabolism and helps coaches compare athletes of different sizes without bias.
Hourly calorie burn
Hourly calorie burn shows how many calories are used each hour at rest. A 1,500 kcal BMR equals about 63 kcal per hour, useful for hospital monitoring or fasting protocols.
Lean mass
Lean mass refers to muscle, bone, organs, and water. Higher lean mass often raises BMR, so athletes with similar weight but more muscle may record higher values than the calculator predicts.
Adaptive thermogenesis
Adaptive thermogenesis captures how metabolism slows or speeds in response to prolonged calorie deficits or surpluses. Tracking BMR over time can flag when the body is adapting to a diet.
Calorie deficit
A calorie deficit occurs when intake falls below expenditure. Knowing BMR prevents aggressive cuts that could compromise recovery or hormone balance.
Maintenance calories
Maintenance calories equal BMR multiplied by an activity factor. Pairing this calculator with the calorie planner estimates the total intake needed to maintain weight.