GLOSSARY
How each calculator works.
A plain-language explanation of every term and calculator on Fitulse. These are wellness estimates using standard, commonly-cited formulas — not medical calculations or a diagnosis.
Body Composition
4- BMI Calculator
- Body Mass Index (BMI) is a simple, widely used screening tool that estimates a person's total body fat category using their height and weight. While it does not measure body fat directly, it serves as an inexpensive and easy-to-perform method to screen for weight categories that may lead to health problems.
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- Body Fat Calculator
- Body fat percentage is the proportion of total body weight that consists of adipose tissue relative to lean mass, which includes muscle, bones, organs, and body fluids. Unlike Body Mass Index (BMI), which evaluates total weight against height, body fat percentage specifically distinguishes tissue composition to provide a clearer insight into metabolic health.
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- Ideal Weight Calculator
- Ideal Body Weight (IBW) is a standardized statistical estimation of a healthy target weight based primarily on an individual's height and biological sex. Originally developed to estimate medical drug dosages in clinical settings, it provides a general weight baseline associated with optimal health outcomes and lower statistical risks of chronic disease for a given height.
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- Waist-to-Height Ratio
- Waist-to-Height Ratio (WHtR) is a simple anthropometric metric calculated by dividing an individual's waist circumference by their height, measured in the same units. It serves as an indicator of central adiposity and body fat distribution rather than overall body mass. A common clinical guideline suggests keeping your waist circumference to less than half your height to reduce cardiometabolic risk.
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Nutrition
5- Calorie Calculator
- Total Daily Energy Expenditure (TDEE) is an estimate of the total number of calories an individual burns in a 24-hour period. It combines an individual's [basal metabolic rate](bmr) with the energy expended through physical activity and food digestion. TDEE represents the caloric intake required to maintain current body weight.
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- Protein Intake Calculator
- Dietary protein intake refers to the total mass of protein consumed through food and dietary supplements over a 24-hour period, typically measured in grams. Protein is an essential macronutrient composed of amino acids required for tissue repair, muscle protein synthesis, enzyme production, and immune function. Daily requirements fluctuate depending on age, total body mass, physical activity level, and specific metabolic or athletic goals.
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- Water Intake Calculator
- Water intake refers to the total volume of fluid consumed through beverages and moisture-rich foods necessary to maintain cellular hydration, physiological function, and fluid balance. Proper hydration supports metabolic processes, body temperature regulation, joint lubrication, cognitive performance, and waste removal. While plain water is the primary source, dietary fluids from fruits, vegetables, and other drinks contribute to overall daily fluid intake.
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- BMR Calculator
- Basal Metabolic Rate (BMR) is the minimum number of calories your body requires to perform basic life-sustaining functions at complete rest over a 24-hour period. These involuntary processes include breathing, circulating blood, cell production, nutrient processing, and maintaining body temperature. BMR represents the largest single component of total daily energy expenditure, typically accounting for 60% to 75% of all calories burned daily.
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- Macro Calculator
- Macronutrients—protein, carbohydrates, and fats—are the primary energy-yielding nutrients required by the human body in large daily quantities. They supply the essential chemical energy and molecular building blocks necessary for metabolic processes, tissue repair, hormone production, and physiological function. Alcohol is also an energy-yielding nutrient providing 7 kcal per gram, though it is non-essential and toxic in excess.
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Activity
3- Steps to Calories
- Steps to calories conversion is a method used to estimate energy expenditure, measured in kilocalories, resulting from physical movement based on daily step count. This metric translates mechanical movement recorded by pedometers or accelerometers into an estimated metabolic cost. It provides a simple, quantitative way to monitor daily physical activity in relation to energy balance goals.
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- Sitting Damage Calculator
- Sedentary risk, colloquially termed sitting damage, refers to the statistical likelihood of metabolic dysfunction, cardiovascular disease, and premature mortality resulting from prolonged, uninterrupted periods of low energy expenditure while sitting or reclining. It measures the independent physiological harm caused by cumulative inactive waking hours, which persists even among individuals who perform daily structured workouts.
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- Resting Heart Rate
- Resting Heart Rate (RHR) is the number of times your heart beats per minute (bpm) while your body is at complete, undisturbed rest. It serves as a foundational clinical marker of cardiovascular fitness, stroke volume efficiency, and autonomic nervous system tone.
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Recovery
1- Sleep Cycle Calculator
- A sleep cycle is an ultradian rhythm lasting approximately 90 to 110 minutes, during which the brain and body progress through distinct stages of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. A typical adult completes four to six continuous sleep cycles per night to support physical restoration, memory consolidation, and metabolic regulation.
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Mental Health
2- Stress Level Test
- Stress level represents a quantified measure of an individual's perceived psychological strain and emotional overload over a specific timeframe. While clinical settings commonly evaluate perceived stress using validated psychometric instruments like the 10-item Perceived Stress Scale (PSS-10) scored on a 0–40 scale, Fitulse's Stress Level Test provides a rapid 5-item screener rated from 1 to 5 across core domains (feeling overwhelmed, irritability, trouble sleeping, concentration difficulties, and physical tension), producing a total cumulative score ranging from 5 to 25.
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- Burnout Risk Test
- Burnout Risk is a quantitative or qualitative measure of an individual's susceptibility to occupational burnout, a state of chronic workplace stress characterized by emotional exhaustion, depersonalization or cynicism, and a reduced sense of personal accomplishment. Recognized by the World Health Organization in the ICD-11, burnout risk evaluates the gap between ongoing work demands and personal recovery capacity before clinical exhaustion occurs. It serves as a preventive screening metric rather than a medical diagnosis.
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Weight Management
3- Weight Loss Timeline
- A weight loss timeline is an estimated timeframe required to achieve a target body weight by maintaining a consistent energy deficit over time. It relies on the principle that a cumulative caloric deficit of approximately 7,700 kilocalories corresponds to the loss of one kilogram of fat mass, though individual metabolic responses vary. Fitulse's calculator uses this metric standard (7,700 kcal/kg) to determine the estimated timeline directly in weeks.
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- Weight Gain Plan
- A weight gain plan is a structured dietary and lifestyle protocol designed to increase total body weight in a controlled, progressive manner. It relies on establishing a consistent caloric surplus, wherein energy intake systematically exceeds total daily energy expenditure. When combined with progressive resistance exercise, a weight gain plan aims to optimize lean muscle tissue synthesis while keeping body fat accumulation within a desired range.
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- Biological Age Calculator
- Biological age, also known as physiological age, measures the functional state of an individual's cells, tissues, and organ systems relative to their chronological age. Unlike chronological age, which measures elapsed calendar time since birth, biological age reflects cumulative biological damage, resilience, and rate of senescence. A biological age lower than one's chronological age indicates superior physiological function and reduced mortality risk.
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