Calories, macros, heart rate and training math.
Free health and fitness tools: TDEE, macros, heart rate zones, one rep max, running pace, body fat, ideal weight and water intake calculators. Informational, private, client-side. All 24 tools below are free, run entirely in your browser, and need no sign-up.
Free macro split calculator. Turn your daily calorie target into protein, carb, and fat grams using a percentage split you choose, all in your browser.
Free daily protein intake calculator. Estimate grams of protein per day from your body weight and activity goal, worked out instantly in your browser.
Free calorie deficit calculator. Enter maintenance calories and a target loss rate to see your daily deficit and adjusted intake, computed in your browser.
Free max heart rate calculator. Estimate your maximum heart rate from age using two proven formulas, side by side, all in your browser.
Free target heart rate zone calculator. Get Karvonen training zones from your age and resting heart rate, calculated instantly in your browser.
Free waist to hip ratio calculator. Divide waist by hip measurement and see the WHO health category by sex, computed instantly in your browser.
Free waist to height ratio calculator. Divide waist by height and see the healthy range guideline, worked out instantly in your browser.
Free lean body mass calculator. Estimate lean mass and fat mass from weight and body fat, or the Boer formula, all in your browser.
Free ponderal index calculator. Compute the corpulence index using weight divided by height cubed, worked out instantly in your browser.
Free body surface area calculator. Estimate BSA in square metres using the Mosteller and Du Bois formulas, side by side, in your browser.
Free running pace to speed converter. Turn minutes per kilometre or mile into km/h and mph, and back again, instantly in your browser.
Free race time predictor. Estimate your finish time at a new distance from a recent race using the Riegel formula, computed in your browser.
Free one rep max calculator with four formulas. Estimate your 1RM from weight and reps using Epley, Brzycki, Lombardi, and Lander in your browser.
Free steps to distance calculator. Convert your step count into kilometres and miles using your height or a custom stride, in your browser.
Free blood alcohol content estimator. Approximate BAC from drinks, weight, sex, and time using the Widmark formula, all in your browser.
Free VO2 max estimator. Approximate your aerobic fitness from a one mile walk test or resting heart rate, calculated in your browser.
Free smoking cost calculator. See how much cigarettes cost you per week, month, year, and decade based on packs and price, in your browser.
Free sleep debt calculator. Compare your recent sleep against a nightly goal to see your accumulated sleep debt for the week, in your browser.
Free ovulation window calculator. Estimate your fertile window and likely ovulation day from your last period and cycle length, in your browser.
Free calories to kilojoules converter. Switch between food calories and kilojoules instantly, both directions, all in your browser.
Free pregnancy week calculator. Find your current gestational week, trimester, and days remaining from your last period, in your browser.
Free BMI Prime calculator. See your BMI as a ratio to the upper healthy limit of 25, with category, computed instantly in your browser.
Free reps per minute calculator. Turn a total rep goal and time limit into a pace, sets, and rest plan for pushups or any exercise, in your browser.
Free water intake calculator in ounces. Estimate daily fluid needs from body weight and activity, shown in ounces, cups, and litres, in your browser.
Yes. Every health & fitness tool on yourhack.ai is completely free, with no sign-up and no usage limits.
Yes. They run in any modern web browser on phone, tablet or desktop. There is nothing to install.
Yes. These tools run entirely in your browser, so nothing you enter is uploaded to a server.
There are currently 24 free health & fitness tools here, and we add more regularly.