This iPhone web app calculator uses a more accurate formula for MHR than the traditional 220-age approach, but you can choose the traditional formula if you want to. Estimate your target heart rate zone using the popular Karvonen Formula. This formula uses both your resting heart rate (RHR) and maximum heart rate (MHR) to calculate a target heart rate (THR) zone for exercise and training. Try with TestiPhone
Welcome to AppSafari. Our team loves apps and is dedicated to writing iPhone app reviews to help you find the best new & free iPhone apps in the App Store. For the latest App Store buzz check out the Trending iPhone apps updated daily with free games worth downloading. Enter our giveaway contest to win free apps every day. You can browse the site in either gallery or list layout.