All Health calculators27 calculators

BMI, calories & fitness tools

• BMI CalculatorCalculate your Body Mass Index (BMI) from height and weight, see your WHO weight category, and find the healthy weight range for your height.
• BMR CalculatorCalculate your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation, the standard for modern nutrition science.
• TDEE CalculatorCalculate your Total Daily Energy Expenditure (TDEE) — how many calories you burn per day based on your BMR and activity level — and get target calories for weight loss, maintenance, or gaining.
• Body Fat CalculatorEstimate your body fat percentage with the U.S. Navy circumference method. Enter neck, waist (and hip for women) measurements to see body fat %, lean mass, and your fitness category.
• Ideal Weight CalculatorFind your ideal body weight using four established formulas — Devine, Robinson, Miller, and Hamwi — based on your height and sex, with a healthy BMI weight range for comparison.
• Water Intake CalculatorCalculate how much water you should drink daily based on your body weight, exercise duration, and climate. Get your daily target in liters, ounces, and glasses.
• Macro CalculatorCalculate your daily protein, carb, and fat targets (macros) from your calories and diet strategy — balanced, low-carb, high-protein, or keto — with gram targets per meal.
• One Rep Max CalculatorEstimate your one-rep max (1RM) for any lift from reps at a lighter weight. See Epley, Brzycki, Lombardi, and Mayhew estimates plus a full percentage training-load table.
• Heart Rate Zone CalculatorCalculate your five heart rate training zones using the Karvonen method (heart-rate reserve). Enter age and resting heart rate to get precise bpm targets for fat burn, aerobic, and anaerobic training.
• Calorie Deficit CalculatorCalculate how long it takes to reach your goal weight with a daily calorie deficit. Enter current weight, target weight, and deficit size to see weekly loss rate and finish date.
• Waist-to-Height Ratio CalculatorCheck your waist-to-height ratio, a simple indicator of metabolic health risk.
• Protein Intake CalculatorFind your daily protein target based on body weight and activity level.
• Walking Calories CalculatorEstimate calories burned walking, adjusted for distance, pace, and body weight.
• Pace from Speed CalculatorConvert a speed in km/h or mph directly into running pace per km or per mile.
• ABSI Calculator (Body Shape Index)Compute A Body Shape Index (ABSI), which uses waist size to refine the health picture BMI misses.
• Cholesterol Ratio CalculatorCheck your total-cholesterol-to-HDL ratio and see what the number suggests about heart risk.
• BAC Calculator (Blood Alcohol Content)Estimate your blood alcohol content from drinks, body weight, sex, and elapsed time — with sober-time projection.
• Pregnancy Weight Gain CalculatorRecommended total and weekly weight gain during pregnancy based on pre-pregnancy BMI (IOM guidelines).
• Ovulation CalculatorPredict your fertile window and next ovulation day from cycle length and the first day of your last period.
• Gestational Age CalculatorConvert weeks + days of pregnancy into trimester, days remaining, and progress percentage — plus estimated conception date offset.
• Caffeine Intake CalculatorTotal your daily caffeine from coffee, tea, energy drinks, and soda, compare against the 400 mg safe limit, and see when to stop for bedtime.
• Podcast Time CalculatorSee how long your podcast backlog takes at normal and sped-up playback, and how much listening time you'd claw back per year.
• Screen Time Budget CalculatorTrack daily screen hours across phone, computer, and TV against recommended limits — and see how many free hours your year could reclaim.
• Caffeine Half-Life CalculatorTrack how much caffeine is still in your system hour by hour — and find the latest safe cutoff time that protects your night's sleep.
• Creatine Dosage CalculatorFind your daily creatine monohydrate dose — loading-phase and maintenance amounts by body weight — plus how long a tub lasts and saturation timing.
• Smoking Cost CalculatorTotal the real cost of smoking — packs, years, and if-invested money — plus life expectancy impact and days of life traded per cigarette.
• Vitamin D Sun Exposure CalculatorEstimate how much midday sun you need for your daily vitamin D — adjusted for skin tone, latitude, and season — plus supplement fallback doses.