Calculate your target heart rate zones for exercise. Shows five zones from 50% to 100% of max heart rate based on your age.
Calculate how much water you should drink daily based on your weight and exercise routine. Essential for hydration tracking.
Calculate estimated due date from the first day of your last menstrual period (LMP). Also shows current gestational age in weeks.
Estimate your body fat percentage from BMI and age using the BMI-based formula for men and women.
Calculate heart rate training zones by age. Find your target heart rate ranges for different exercise intensity levels.
Calculate rate limit windows, burst allowances, and retry intervals. Design effective rate limiting for your API endpoints.
Target Heart Rate Zones lets you calculate your target heart rate zones for exercise. Shows five zones from 50% to 100% of max heart rate based on your age.. Everything runs inside your browser — nothing is uploaded to a server. It works on any device with a modern web browser.
Calculate your target heart rate zones for exercise. Shows five zones from 50% to 100% of max heart rate based on your age. It's ideal for developers, designers, and anyone who needs to calculate your target heart rate zones for exercise without installing software or sending data to external servers.
Direct text entry, file upload, or URL-based input — depending on the tool. All numeric values are entered through input fields with real-time updates.
Yes. After the initial page load, Target Heart Rate Zones runs entirely on your device with no internet connection needed. All processing is done locally.
Yes, this tool is completely free. No credit card or registration is required for standard usage.
All processing happens 100% locally in your browser. Your data is never uploaded to any server.
Yes. Once the page has loaded, the tool runs entirely offline without requiring an internet connection.
Standard tools are unlimited. Pro tools allow free daily usage with an option to upgrade.
Any modern web browser (Chrome, Firefox, Safari, Edge) on desktop or mobile. No installation needed.
Health Toolkit
Calorie tracker with common foods database, waist-to-hip ratio calculator, and body fat percentage estimator. (BMI and BMR have their own dedicated pages.)
Body Fat Estimator
Estimate body fat percentage using BMI-based formula adjusted for age and gender. Shows fitness range and category.
Daily Calorie Needs
Calculate your daily calorie needs using BMR and activity level. Shows maintenance, cutting, and bulking calorie targets for fitness planning.
Daily Macronutrients
Calculate recommended daily protein, carbs, and fat grams based on calorie intake. Follows standard 30/40/30 macro split.
Daily Water Intake
Calculate how much water you should drink daily based on your weight and exercise routine. Essential for hydration tracking.
Sleep Requirements
Get recommended sleep hours based on your age. Follows CDC and National Sleep Foundation guidelines from newborn to senior.