Health & Fitness Calculators
Calorie, TDEE, BMR, body fat, macro, ideal weight, water intake and running pace calculators. Metric and imperial, instant results, nothing ever uploaded.
62 free tools
Calorie Calculator
Work out how many calories you need each day to lose, maintain or gain weight, using the Mifflin-St Jeor equation with metric or imperial units.
TDEE Calculator
Estimate your total daily energy expenditure from BMR and activity level, with Mifflin-St Jeor and Katch-McArdle options and a full activity comparison table.
BMR Calculator
Calculate your basal metabolic rate with Mifflin-St Jeor, revised Harris-Benedict or Katch-McArdle, in metric or imperial, and compare all three side by side.
Body Fat Calculator
Estimate body fat percentage with the US Navy circumference method using neck, waist and hip measurements, and see your fat mass and lean mass in kg or lb.
Lean Body Mass Calculator
Calculate lean body mass and fat mass from height and weight using the Boer, James and Hume formulas, or directly from a known body fat percentage.
Ideal Weight Calculator
Find your ideal body weight for your height using the Robinson, Miller, Devine and Hamwi formulas, plus the healthy BMI range, in kg or pounds.
Macro Calculator
Turn a daily calorie target into grams of protein, carbohydrate and fat using preset or custom macro splits, with a per-meal breakdown and metric or imperial input.
Protein Intake Calculator
Work out how much protein to eat per day in grams, based on your body weight and training goal, with metric and imperial input and a per-meal split.
Water Intake Calculator
Estimate how much water to drink each day from your body weight, exercise time and climate, with results in litres, millilitres, US fluid ounces and glasses.
Waist to Hip Ratio Calculator
Calculate your waist-to-hip ratio and waist-to-height ratio from tape measurements in centimetres or inches, with the WHO risk bands for men and women.
Pace Calculator
Calculate running pace, finish time or distance from any two of the three, in min/km or min/mile, with equivalent times for 5K, 10K, half and full marathon.
Steps to Calories Calculator
Convert daily steps into calories burned and distance walked, using stride length from your height, your body weight and MET values for walking pace.
Due Date Calculator
Estimate your pregnancy due date from your last period, conception date or IVF transfer, with gestational age today and trimester dates using Naegele's rule.
Sleep Cycle Calculator
Find the best times to go to bed or wake up based on 90-minute sleep cycles, including the time it takes you to fall asleep. Works forwards and backwards.
Ovulation Calculator
Estimate your ovulation day and six-day fertile window from your last period and cycle length, projected across the next six cycles.
Period Calculator
Predict your next period start and end dates from your last period, cycle length and period duration, shown on a shaded calendar.
Pregnancy Week Calculator
Work out how many weeks and days pregnant you are, plus your trimester and due date, from your last period, conception date or a known due date.
Target Heart Rate Calculator
Calculate your target heart rate zones with the Karvonen reserve method and the percent-of-maximum method, from an estimated or measured maximum heart rate.
One Rep Max Calculator
Estimate your 1RM from a set of reps using the Epley, Brzycki, Lombardi, Wathen and O'Conner formulas side by side, with a training load table.
A1C Calculator
Convert HbA1c to estimated average glucose and back using the ADAG equation, in mg/dL and mmol/L, with IFCC units and ADA reference bands.
Blood Pressure Calculator
Classify a blood pressure reading against the 2017 ACC/AHA categories and calculate pulse pressure and mean arterial pressure, with an averaging mode.
Body Surface Area Calculator
Calculate body surface area in m² with the Du Bois, Mosteller, Haycock, Boyd and Gehan-George formulas side by side, in metric or imperial units.
VO2 Max Calculator
Estimate VO2 max from a Cooper 12-minute run, a Rockport one-mile walk or your resting heart rate, then compare it against age and sex fitness norms.
Calories Burned Calculator
Calculate calories burned from MET values for 57 activities, using the ACSM equation kcal = MET × 3.5 × kg ÷ 200 × minutes, in kg or lb.
Race Time Predictor
Predict your 5K, 10K, half marathon and marathon times from one recent race using Riegel's formula, with pace per km and per mile for each.
Weight Loss Percentage Calculator
Calculate what percentage of your body weight you have lost, your weekly rate, progress towards a goal weight and a projected goal date.
Calorie Deficit Calculator
Work out the daily calorie deficit and intake target needed to reach a goal weight by a chosen date, with a safe intake floor and a weekly loss rate check.
Net Carbs Calculator
Add up net carbs from nutrition labels by subtracting fibre and sugar alcohols, with erythritol excluded, and track the day's total against your carb limit.
Glycemic Load Calculator
Calculate glycemic load from glycemic index and carbs per serving, using a built-in table of 65 common foods, with low/medium/high bands and a daily total.
Alcohol Calories Calculator
Calculate the calories in beer, wine, spirits and cocktails from volume and ABV, plus standard drinks and units, with a weekly total across your drinks.
Blood Alcohol Calculator
Estimate blood alcohol concentration with the Widmark equation from body weight, drinks and time elapsed, with an editable r factor and elimination rate.
Caffeine Half-Life Calculator
See how much caffeine is still in your system at bedtime by modelling each coffee, tea and energy drink with an editable half-life and a decay curve.
Intermittent Fasting Calculator
Build a 16:8, 18:6, 20:4, OMAD, 5:2 or alternate-day fasting schedule from your first or last meal, with window times, a live countdown and a 7-day plan.
Sweat Rate Calculator
Calculate your sweat rate in litres and fluid ounces per hour from pre and post exercise weights, with replacement volumes and an estimated sodium loss.
Cholesterol Ratio Calculator
Calculate total:HDL, LDL:HDL and triglyceride:HDL ratios plus non-HDL cholesterol and Friedewald LDL, in mg/dL or mmol/L, against standard reference bands.
eGFR Calculator
Estimate kidney function with the race-free CKD-EPI 2021 creatinine equation plus Cockcroft-Gault clearance, with µmol/L switching and KDIGO staging.
IV Drip Rate Calculator
Nursing infusion maths in one place: drops per minute from a drop factor, pump rate in mL/hour, infusion time, and mcg/kg/min to mL/hour conversion.
Smoking Cost Calculator
See what smoking costs per day, month, year and decade, what the same money would grow to if invested, and how much you have saved since your quit date.
FFMI Calculator
Work out your fat-free mass index and height-adjusted FFMI from weight, height and body fat, with the usual interpretation bands and their limits.
Wilks Calculator
Score a powerlifting total with the Wilks coefficient and DOTS side by side, in kilograms or pounds, for the three-lift total or a single lift.
Barbell Plate Calculator
Work out exactly which plates go on each side of the bar for any target weight, using only the plates you own, plus a matching warm-up ladder.
Cycling Power Calculator
Estimate the watts needed for a given cycling speed, or the speed a given power buys you, from CdA, rolling resistance, gradient, wind and air density.
Swim Pace Calculator
Convert swim times to pace per 25, 50 and 100 in metres and yards, convert between pool courses, build split ladders and calculate SWOLF.
Steps to Miles Calculator
Convert steps to miles and kilometres using a stride length estimated from your height, or your own measured stride, plus the reverse calculation.
Waist to Height Ratio Calculator
Divide your waist by your height to get your WHtR, read it against the 0.4, 0.5 and 0.6 screening boundaries, and compare it with your BMI.
Conception Date Calculator
Work back from a due date, last period or ultrasound to the likely conception window, with cycle length taken into account and a full timeline.
Pregnancy Weight Gain Calculator
Compare your weight gain with the Institute of Medicine ranges for your pre-pregnancy BMI, week by week, for a singleton or twin pregnancy.
Child Height Predictor
Predict a child's adult height with the mid-parental method from both parents' heights, with a realistic range and the double-height-at-two cross-check.
Dog Age Calculator
Convert dog years to human years with the epigenetic clock formula and the size-band table side by side, plus the reverse and a cat conversion.
Sleep Debt Calculator
Log up to fourteen nights against your sleep target to see your running sleep debt, how long it takes to repay, and bedtimes in 90-minute cycles.
Anion Gap Calculator
Calculate the serum anion gap, the potassium-inclusive variant, the albumin-corrected gap and the delta ratio, with editable reference ranges.
Corrected Calcium Calculator
Adjust total serum calcium for a low albumin using Payne's correction, in mg/dL or mmol/L, with an editable factor and reference range.
QTc Calculator
Correct a measured QT interval for heart rate with Bazett, Fridericia, Framingham and Hodges side by side, using editable prolongation thresholds.
Blood Volume Calculator
Estimate total blood volume with Nadler's equations and Gilcher's rule of five, plus red cell mass, plasma volume and maximum allowable blood loss.
Creatinine Clearance Calculator
Estimate creatinine clearance with the Cockcroft-Gault equation using actual, ideal or adjusted body weight, in mg/dL or µmol/L.
Parkland Formula Calculator
Work out 24-hour burn fluid resuscitation from weight and %TBSA, with a rule-of-nines picker, hourly rates and a catch-up rate from the injury time.
Pediatric Dosage Calculator
Convert a mg per kg paediatric dose into milligrams and millilitres, apply single and daily maximums, and compare Clark's and Young's rules.
APGAR Score Calculator
Score a newborn's appearance, pulse, grimace, activity and respiration at 1, 5 and 10 minutes, with totals, bands and a copyable summary.
Glasgow Coma Scale Calculator
Score eye, verbal and motor responses to get a GCS total in E V M notation, with a paediatric scale and proper not-testable handling.
CHA₂DS₂-VASc Calculator
Score stroke risk in atrial fibrillation with CHA2DS2-VASc, read the annual risk from an editable table, and compute HAS-BLED alongside it.
Alcohol Units Calculator
Add up UK alcohol units, national standard drinks, grams of pure ethanol and calories across a week of drinks, with editable national standards.
Dog Food Portion Calculator
Work out how much to feed a dog each day from resting energy requirement, a life-stage factor and the food's calorie density, in grams and cups.