Free health & fitness calculators — smart, fast, no sign-up required
Whether you're tracking weight loss, planning workouts, or just curious about your health numbers — our calculators give you instant, science-backed results. BMI to screen for weight categories. Calorie burn estimates for 10+ activities. BMR to understand your baseline metabolism. Ideal weight using 5 different medical formulas. Plus advanced tools like Beyond BMI (5 body metrics that are actually better than BMI) and the Plateau Diagnostic (figure out why your weight stopped moving). All calculations run in your browser — nothing is sent anywhere, no account needed, no email required. Just type your numbers and get results instantly.
Every calculator uses formulas validated by peer-reviewed research — Mifflin-St Jeor for BMR, the standard BMI equation, MET-based calorie estimates, and 5 medical formulas for ideal weight. No bro science, no fad diet formulas.
Your numbers stay on your device. No health data leaves your browser — no data stored on any server, no account required, no email collection. Calculations run entirely in JavaScript on your machine.
Most sites give you one number and call it a day. We give you context — comparison tables, healthy ranges, visual gauges, and downloadable reports. Plus tools like Beyond BMI and Plateau Diagnostic you won't find anywhere else for free.
The quickest way to check if your weight is in a healthy range. Enter your height and weight, and the calculator gives you your BMI number plus your weight category. Includes a visual gauge that shows where you fall on the underweight-to-obese spectrum. Free, instant, and you can download a full report with personalized recommendations.
Find out how many calories you actually burn during exercise — because "I worked out" doesn't mean the same thing for everyone. Covers 10 activities from walking to HIIT, calculated for your exact bodyweight and workout duration. See calories burned per session and per hour, so you can compare activities and plan your workouts smarter.
Your BMR is how many calories your body burns just to stay alive — no exercise, no movement, just keeping your organs running. We use 3 different formulas (Mifflin-St Jeor, Cunningham, and Harris-Benedict) and show you the median for the most reliable estimate. Also calculates your TDEE at 5 activity levels so you know exactly how much to eat for any goal — fat loss, maintenance, or muscle gain.
How much should you weigh? Instead of one guess, this calculator runs 5 different medical formulas (Robinson, Miller, Devine, Hamwi, and Peterson) and shows you the range they all agree on. The median across all 5 formulas is your recommended target. Works with just your height and gender — no body fat estimation needed.
In-depth articles to help you understand your body beyond the numbers
BRI, WHtR, WHR, Body Fat %, FFMI — why BMI alone isn't enough and how to measure what counts.
2026-06-20Metabolic adaptation, tracking errors, NEAT reduction, water retention, muscle gain — diagnose and break through.
2026-06-20Macro splits by goal, diet approach comparisons, adjustment protocols, and quick hand-calculation formulas.
2026-06-20记录每日体重、饮食和运动，获取 AI 生成的周报分析和个性化建议
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