Health Tools
BMI, calorie, and fitness tools
Estimate BMI, BMR, TDEE, calorie burn, heart rate zones, sleep cycles, ideal weight, and more using the same published clinical formulas a doctor's office or fitness app would reference — Mifflin-St Jeor, the Karvonen method, WHO classification bands — shown alongside the result rather than hidden behind a black box. Useful whether you're starting a fitness routine, adjusting a diet plan, or just curious what a number on a chart actually means for you. Every calculation runs on-device: the age, weight, and health details you type in are never sent to a server, and results always come with the formula's assumptions and limits stated plainly (see our disclaimer).
All Health Tools
11 tools, grouped by what you're trying to do.
Measure
Health Metrics Studio
Calculate BMI, BMR, TDEE, daily calories, macros, healthy weight, protein, water intake and more with ForgePlug's free global Health Metrics Studio.
Body Fat Calculator
Estimate body fat percentage using the US Navy Method or the Jackson-Pollock skinfold method, compare with a BMI estimate, and calculate lean body mass and fat mass — free, private, and browser-only.
Ideal Weight Calculator
Calculate your ideal body weight using Devine, Robinson, Miller, and Hamwi formulas plus the WHO healthy weight range for your height.
Calculate
Calorie Burn Calculator
Estimate calories burned during 25+ activities — running, cycling, swimming, HIIT, yoga and more. MET-based, browser-only, free.
Running Pace Calculator
Calculate running pace, speed, and splits for any distance. Predict 5K, 10K, half marathon and marathon race times with the Riegel formula.
Heart Rate Zone Calculator
Calculate your 5 training heart rate zones (Z1–Z5) using the 220-age or Tanaka formula, plus Karvonen heart-rate-reserve method.
Step Calculator
Convert steps to distance, distance to steps, and estimate calories burned while walking. Based on your height for accurate step length.
Plan
Nutrition Studio
Generate personalized diet plans, weekly meal planners, grocery lists, macro targets and smart food substitutions with ForgePlug's free Nutrition Studio.
Sleep Calculator
Find the ideal bedtime or wake time based on 90-minute sleep cycles. Wake up refreshed with 4–6 full cycles of quality sleep.
Pregnancy Due Date Calculator
Estimate your due date from your last menstrual period or conception date using Naegele's rule. See your current week, trimester, and key milestones.
Intermittent Fasting Timer
Track your intermittent fasting windows live. Pick a schedule like 16:8 or 18:6, start the timer, and watch your fasting and eating phases update in real time.
Recently Added
The newest tools in this category.
Nutrition Studio
Generate personalized diet plans, weekly meal planners, grocery lists, macro targets and smart food substitutions with ForgePlug's free Nutrition Studio.
Health Metrics Studio
Calculate BMI, BMR, TDEE, daily calories, macros, healthy weight, protein, water intake and more with ForgePlug's free global Health Metrics Studio.
Calorie Burn Calculator
Estimate calories burned during 25+ activities — running, cycling, swimming, HIIT, yoga and more. MET-based, browser-only, free.
Running Pace Calculator
Calculate running pace, speed, and splits for any distance. Predict 5K, 10K, half marathon and marathon race times with the Riegel formula.
Guides for Health Tools
Learn the formulas, assumptions, and best practices behind health tools in our Health Guides.
How to Use TDEE to Set a Realistic Calorie Target
TDEE tells you how many calories you burn in a day — but the number alone doesn't tell you what to eat. Here's how to turn it into a real calorie target.
Understanding BMI's Limits and What to Use Instead
BMI is the most widely used health number in the world — and the most widely misunderstood. Here's what it can tell you and what it can't.
How TDEE Estimates Your Daily Calorie Needs
Your Total Daily Energy Expenditure is the number behind every calorie target. Here's how it's estimated from BMR and activity, with a worked example.
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Health Tools — Frequently Asked Questions
Common questions about using health tools on ForgePlug.