Training and weight goals, in numbers
Fitness calculators estimate the numbers behind a training or weight goal: how many calories you burn just being alive, how many you should eat to lose or gain, and how your body composition is changing while the scale barely moves. They are estimates, built from population averages and your height, weight, age and activity level, so treat them as a starting point you adjust with real results.
Most people start with BMI and the calorie calculator. BMI is a blunt screening number, useful for a first look and misleading for anyone carrying much muscle, which is why the body fat and lean body mass calculators sit right next to it. Set a calorie target with the calorie and macro calculators, split it into protein, carbs and fat with the macro and protein tools, then give the plan two to three weeks before you judge it. If your weight trend disagrees with the target, the trend wins and the target moves.
Runners and lifters get their own corners here. The pace calculator turns a target time into splits you can actually hold, the calories burned tool prices a session honestly, and the army body fat calculator follows the tape test method used for service standards. The healthy weight and body type tools are there for the question everyone asks first: what should someone my height weigh, roughly?
All 14 fitness calculators are free and run in your browser, with nothing to sign up for and nothing stored. Your measurements stay on your device. Use the numbers to plan, then let the mirror, the tape and your training log have the last word. Bodies are individuals, and any calculator that forgets that is selling you something.