Disclaimer: These calculators provide educational estimates only. They are not medical advice, diagnosis or treatment. Speak with a qualified professional if you have a medical condition, take medication, are pregnant, or have specific clinical needs.

Calories

TDEE / Calorie Calculator

Estimate your daily energy expenditure with the Mifflin-St Jeor equation, then see practical fat loss and lean bulk targets.

Sex

Age

Units

Activity

Weight

Height

Method: BMR uses the Mifflin-St Jeor formula, then multiplies by activity level. For nutrition strategy, see fat loss, muscle growth and the macro calculator.

Estimated result

maintenance calories/day

Fat loss target--

Lean bulk target--

Estimated BMR--

Nutrition

Macro Calculator

Turn your calorie target into protein, carbohydrates and fats using practical evidence-based defaults.

Calories/day

Weight unit

Body weight

Goal

Preference

Method: Protein is set around 1.6-2.2 g/kg depending on goal, fat around 20-30% of calories, and carbs fill the remaining calories. Pair this with the whey protein hub if protein intake is hard to hit.

Daily macros

grams protein

Carbs--

Fats--

Protein target--

Protein

Daily Protein Calculator

Estimate a daily protein range for general fitness, muscle gain or fat loss.

Body weight

Unit

Goal

Method: General fitness uses 1.2-1.6 g/kg, muscle gain uses 1.6-2.2 g/kg, and cutting uses 1.8-2.4 g/kg. Useful next: whey protein guide and best whey protein.

Recommended range

grams/day

Lower target--

Higher target--

Body Composition

Body Fat Percentage Calculator

Estimate body fat percentage using the US Navy circumference method.

Sex

Unit

Height

Neck

Waist

Hips (women)

Method: US Navy equations use height, neck, waist and hips for women. This is a field estimate, not a DEXA scan.

Estimated body fat

percent body fat

Estimated lean mass--

Next toolCalculate FFMI

Strength

One Rep Max Calculator

Estimate your one-rep max from a submaximal set using the Epley formula.

Weight lifted

Unit

Reps completed

Formula: 1RM = weight x (1 + reps / 30). Useful next: strength training, training equipment and adjustable dumbbells.

Estimated 1RM

90%--

80%--

70%--

Creatine

Creatine Dosage Calculator

Estimate a daily creatine monohydrate dose, optional loading phase and maintenance target.

Body weight

Unit

Goal

Method: Standard maintenance is usually 3-5 g/day. Loading can use about 0.3 g/kg/day for 5-7 days, then maintenance around 0.03 g/kg/day or 3-5 g/day. Useful next: creatine benefits guide and best creatine supplements.

Creatine dose

grams/day

Maintenance--

Optional loading--

Caffeine

Caffeine Dosage Calculator

Estimate pre-workout caffeine ranges based on body weight and sensitivity.

Body weight

Unit

Sensitivity

Method: Low dose is about 1-2 mg/kg, moderate is about 3 mg/kg, and high performance protocols can reach 5-6 mg/kg. Avoid late-day use and do not exceed personal or medical limits. Useful next: caffeine benefits guide and best pre-workout supplements.

Caffeine dose

mg before training

Low range--

High cautionAvoid late-day use. Many adults should stay below about 400 mg/day total caffeine.

Hydration

Water Intake Calculator

Estimate daily water needs from body weight, training intensity and climate.

Body weight

Unit

Training

Climate

Method: Base intake uses roughly 30-40 ml/kg/day, then adds estimated fluid for training and heat. Useful next: electrolytes and sports hydration if those pages are available in your content plan.

Daily water estimate

liters/day

Base range--

Training and heat add-on--

Body Composition

Lean Body Mass Calculator

Calculate lean body mass from body weight and body fat percentage.

Body weight

Unit

Body fat (%)

Formula: Lean body mass = body weight x (1 - body fat percentage / 100).

Lean body mass

Fat mass--

Next toolCalculate FFMI

Body Composition

FFMI Calculator

Estimate fat-free mass index and normalized FFMI from height, weight and body fat percentage.

Units

Weight

Height

Body fat (%)

Formula: FFMI = lean mass in kg / height in meters squared. Normalized FFMI adjusts to a reference height of 1.8 m.

Estimated FFMI

fat-free mass index

Normalized FFMI--

Lean mass--

Body Composition

Ideal Weight Calculator

Estimate a healthy weight range using the Devine and Hamwi formulas — widely used clinical reference ranges for adults.

Sex

Units

Height

Methods: Devine (1974): 50 kg + 2.3 kg/inch over 5 ft (males). Hamwi (1964): 48 kg + 2.7 kg/inch (males). Results are clinical reference ranges, not body composition goals.

Ideal weight range

Devine formula--

Hamwi formula--

Healthy BMI range--

Cardio Training

Heart Rate Zone Calculator

Calculate your 5 training heart rate zones from max HR or age. Use these zones to structure Zone 2 cardio, threshold work, and HIIT sessions.

Age

Max HR (optional)

Method: Max HR estimated as 220 − age (Tanaka formula gives similar results). Zone 1: <57% max, Zone 2: 57–63%, Zone 3: 64–76%, Zone 4: 77–95%, Zone 5: 96–100%. Zone 2 is the aerobic base zone, critical for VO₂ max and longevity.

Your max HR

beats per minute

Zone 1 (Recovery)--

Zone 2 (Aerobic base)--

Zone 3 (Aerobic power)--

Zone 4 (Threshold)--

Zone 5 (VO₂ max / HIIT)--

Cardio Fitness

VO₂ Max Estimator

Estimate aerobic capacity from resting heart rate using the Uth–Sørensen–Overgaard–Pedersen equation. Higher VO₂ max is the strongest predictor of longevity.

Resting Heart Rate (bpm)

Age

Formula: VO₂ max ≈ 15 × (Max HR / Resting HR). Max HR estimated as 220 − age. Measure resting HR first thing in the morning before getting up for best accuracy.

Estimated VO₂ Max

ml/kg/min

Fitness level--

All-cause mortality percentile--

Target (top quartile for age)--

Cardio

Running Calorie Calculator

Estimate calories burned running based on body weight, distance, and pace using MET values from the Compendium of Physical Activities.

Body weight

Unit

Distance

Distance unit

Pace

Method: Calories = MET × weight (kg) × duration (hours). MET values from Compendium of Physical Activities. Net calories shown (subtract resting metabolic rate for gross).

Estimated calories burned

kcal

Duration--

Per km / mile--

MET value used--

Recovery

Sleep Cycle Calculator

Sleep occurs in ~90-minute cycles. Find ideal bedtimes or wake times that align with natural sleep stages so you wake refreshed, not mid-cycle.

Calculate

Time

Target sleep cycles

Science: Average sleep cycle = 90 minutes (NREM 1–3 + REM). 5 cycles = 7.5 hours — the most common optimal range. Add 15 minutes to account for sleep onset. Waking between cycles is associated with better alertness and lower sleep inertia.

Ideal times

Based on 5 sleep cycles (7.5 hours)

Option 1 (4 cycles)--

Option 2 (5 cycles)--

Option 3 (6 cycles)--