Health & fitness
374 health and fitness calculators: body mass index, calories, ideal weight, heart rate zones, pregnancy dates, hydration and training loads. Clear results with the formula behind them, free in your browser. They inform, they do not diagnose.
BMI calculator
70 kg at 175 cm gives a BMI of 22.9, inside the WHO normal range of 18.5 up to 25. Enter weight and height in metric or imperial units and get your body mass…
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Sleep calculator
Plan sleep in whole 90-minute cycles. To wake at 07:00 after 5 cycles, with 15 minutes to fall asleep, go to bed at 23:15.
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TDEE & BMR calculator
An 80 kg, 180 cm, 30-year-old man with a sedentary routine burns 1,780 kcal at rest and needs 2,136 kcal a day to keep his weight, by the Mifflin-St Jeor…
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One rep max calculator
Turn a hard set into a one-rep max estimate without testing a true max: 100 for 5 reps gives 116.67 with Epley and 112.5 with Brzycki.
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Body fat calculator
A man 180 cm tall with a 38 cm neck and an 85 cm waist comes out at 16.1% body fat, in the fitness range.
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Due date calculator
Estimate your due date from the first day of your last period: a period starting 1 January 2026 with a 28-day cycle gives 8 October 2026, 280 days later, plus…
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Heart rate zones
At 30 years old with a resting pulse of 60, your endurance zone runs from 138 to 151 beats per minute.
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Ideal weight calculator
For a man 180 cm tall, ideal body weight comes out at 72.6 kg with Robinson, 71.5 kg with Miller and 75.0 kg with Devine.
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Ovulation calculator
From the first day of your last period, see your likely ovulation day, fertile window and next period: a period starting 1 March 2026 with a 28-day cycle points…
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Water intake calculator
At 70 kg, moderate activity and a temperate climate, the estimate is 2818 ml, or 2.82 litres, a day: enter your weight, activity level and climate to get a…
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A1C converter
An A1C of 7% matches an estimated average glucose of 154.2 mg/dL under the ADA formula. Convert either way to understand a lab report or a lesson, then discuss…
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BAC calculator
A 70 kg man who had 2 standard drinks is estimated at 0.0288 % blood alcohol after 2 hours under the Widmark model.
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Macro calculator
Split a daily calorie target into protein, carbohydrate and fat: 2000 kcal at 30/40/30 gives 150 g of protein, 200 g of carbs and 66.7 g of fat.
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Plate calculator
Type the weight you want on the bar and see exactly which plates go on each side: 100 kg on a 20 kg bar means 40 kg per side, one 25 and one 15.
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Mifflin-St Jeor BMR calculator
Get the modern clinical estimate of your resting calorie floor: with Mifflin-St Jeor, a 30-year-old man of 80 kg and 180 cm burns 1780 kcal a day at complete…
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Caffeine dose by body weight
Multiply body weight by a target in mg per kg: 70 kg at 3 mg/kg is 210 mg of caffeine. Use the rate your coach, protocol or clinician set, then compare the…
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eGFR kidney function calculator
A 50-year-old woman with a serum creatinine of 1 mg/dL has an eGFR of 68.6 mL/min/1.73 m², stage G2.
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Fat mass from body fat %
Converts a body-fat percentage into kilograms: 80 kg at 22.5% body fat is 18 kg of fat mass and 62 kg of lean mass.
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Ponderal index calculator
A weight of 70 kg at 1.75 m gives a ponderal index of 13.061224 kg/m³. Dividing by height cubed instead of squared ranks very tall, very short and growing…
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Calorie deficit calculator
Losing 5 kg in 70 days on 2500 kcal of maintenance means a 550 kcal daily deficit and an intake of about 1950 kcal.
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Cycling speed from power calculator
At 200 W with 80 kg of rider and bike on flat ground, you hold roughly 33 to 34 km/h. Change power, weight, grade, wind or aerodynamics to see the steady speed…
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Body frame size calculator
Classifies your skeletal frame as small, medium or large from height and wrist size: a 175 cm man with a 17.5 cm wrist has a ratio of 10, which is medium.
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Lean body mass calculator
An 80 kg man who is 180 cm tall has about 61.42 kg of lean mass by the Boer equations. Enter weight, height and sex to see how much of your weight is muscle…
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Maximum heart rate calculator
At 40, the Fox and Tanaka formulas both predict a maximum of 180 bpm and Gulati predicts 170.8, an average of 176.93.
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Pace to speed converter
A pace of 5:30 per kilometre is just under 11 km/h, the number to set on a treadmill. Type your pace per kilometre or per mile and get the matching speed in…
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Pulse pressure calculator
A reading of 120 over 80 has a pulse pressure of 40 mmHg, in the normal band of 40 to 60. Enter the top and bottom numbers from your cuff to see the gap between…
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Swimming calorie calculator
Estimate the calories you burn in the pool from time, body weight and effort: a 70 kg swimmer at moderate intensity for 45 minutes burns about 436 kcal, or 9.68…
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Rockport one-mile walk VO2 max calculator
A 40-year-old man weighing 70 kg who walks a mile in 15:30 and finishes with a heart rate of 140 has an estimated VO2 max of 39.2766 mL/kg/min.
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Walking calorie calculator
A 70 kg walker at 12 minutes per kilometre covers 5 km in 60 minutes at 5 km/h and burns about 248 kcal on flat ground.
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Anion gap calculator
Get the serum anion gap and its albumin-corrected value in one step: sodium 140, chloride 104 and bicarbonate 24 mEq/L give a gap of 12.
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Blood pressure category calculator
Put an adult blood pressure reading into its ACC/AHA 2017 category: 118/76 mmHg is normal, while 125/82 is already stage 1 because the diastolic number reached…
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BMI Prime calculator
Express a BMI as a ratio to the upper-normal limit of 25: a BMI of 22.5 gives a BMI Prime of 0.9, which is 90% of the limit, so it plainly sits below it.
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Harris-Benedict BMR calculator
Find your resting calorie baseline with the revised Harris-Benedict equation from 1984: a 30-year-old man weighing 80 kg at 180 cm burns 1,853.632 kcal a day at…
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Katch-McArdle BMR calculator
At 80 kg and 20% body fat you carry 64 kg of lean mass, and the Katch-McArdle equation puts your resting burn at 1752.4 kcal a day, because it counts lean…
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Total body water calculator
Estimate how much water your body holds with the Watson equations from 1980: a 30-year-old man at 180 cm and 80 kg carries 45.9282 litres, which is 57.41025% of…
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Body surface area Du Bois calculator
Get body surface area from the Du Bois formula of 1916: 0.007184 times height in cm to the power 0.725 times weight in kg to the power 0.425.
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Body surface area calculator
Multiply height in cm by weight in kg, divide by 3600 and take the square root: for 170 cm and 70 kg the product is 11900.
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Calories burned calculator
Multiply the activity MET by your weight in kg and the hours of exercise: MET 8 at 70 kg for 30 minutes is 280 kcal, or 560 kcal per hour.
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Child and teen BMI calculator
An 8-year-old boy weighing 32 kg at 132 cm lands in the overweight band, between the 85th and 95th percentile for his age.
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Corrected calcium calculator
With calcium at 8 mg/dL and albumin at 3 g/dL, the Payne formula adds 0.8 and gives a corrected calcium of 8.8.
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Cycling calorie calculator
A 70 kg rider at moderate effort for 60 minutes burns about 476 kcal, using MET 6.8 times weight times hours.
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Fat-free mass index calculator
Scores your lean mass against your stature: at 80 kg, 1.8 m and 15% body fat, 68 kg of lean mass is divided by height squared to give FFMI in kg/m².
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Daily fiber intake calculator
Turns your daily calories into a fiber target: a 35-year-old woman eating 2000 kcal gets 28 g a day, shown beside the 25 g Adequate Intake for her age and sex.
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Mean arterial pressure calculator
A reading of 120/80 mmHg gives a mean arterial pressure of about 93.3 and a pulse pressure of 40. Enter your systolic and diastolic numbers to get the average…
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Pack years calculator
Smoking 20 cigarettes a day for 10 years adds up to 10 pack-years. Enter the average number smoked per day and how long that lasted to get the exposure figure…
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Pregnancy weight gain calculator
With a pre-pregnancy BMI of 22, the recommended gain by week 20 is 4.5 to 6 kg, on the way to 11.5 to 16 kg at term.
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Daily protein intake calculator
At 70 kg and 1.6 g of protein per kilo, your daily total is 112 g. You choose the multiplier from your coach, sport guidelines or clinician, and the calculator…
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Riegel race time predictor
A 10K run in 40:00 predicts 1:28:15 for a half marathon with Riegel's formula and its classic 1.06 exponent.
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Running calorie calculator
Running 10 km at 70 kg on flat ground burns about 700 kcal net, roughly 1 kcal per kilo per kilometre.
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Running pace calculator
Run 10 km in one hour and your pace is 6:00 per kilometre, or 9:39 per mile, at an average of 10 km/h.
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Steps to distance calculator
Multiply your steps by your step length to get the distance walked: 10000 steps at 0.75 m is 7500 m, or 7.5 km.
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Swimming pace calculator
Enter a distance and finish time to get your pace per 100 m and per 100 yards: 1500 m in 20 minutes is 1:20 per 100 m, about 1:13 per 100 yd, plus your speed.
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Target heart rate Karvonen calculator
A 30-year-old with a resting pulse of 60 who trains at 70% of reserve should aim for 151 beats per minute.
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VO2 max Cooper test calculator
Covering 2800 metres in the Cooper 12-minute test gives an estimated VO2 max of about fifty-one mL/kg/min.
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Waist-to-height ratio calculator
An 80 cm waist with a height of 170 cm gives a ratio of 0.47, inside the healthy band below 0.5. Enter both measurements in the same unit and see your band at…
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Waist-to-hip ratio calculator
A woman with an 80 cm waist and 100 cm hips has a ratio of 0.8, right where the moderate band starts.
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Adjusted body weight calculator
Blend actual and ideal weight into one adjusted figure: at 100 kg actual and 70 kg ideal, the excess is 30 kg and the adjusted body weight is 82 kg, using the…
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Appendicular skeletal muscle mass calculator
Estimate the muscle in the arms and legs without a scan: a 65-year-old man of 75 kg and 175 cm has about 24.007 kg of limb muscle and an index of 7.839 kg/m²…
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Original Harris-Benedict 1919 BMR calculator
Reproduce the classic 1919 Harris-Benedict result exactly: a 30-year-old man of 80 kg and 180 cm comes out at 1,864.545 kcal a day.
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Mueller equation BMR calculator
Get a composition-aware resting calorie floor from four simple measurements: a 30-year-old man of 80 kg and 180 cm splits into 61.42 kg lean and 18.58 kg fat…
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