Free personalized heart rate training zones (Karvonen formula)
Launch week is coming up. This startup will launch on July 5, 2026 and start accepting upvotes then.
Most heart rate calculators use 220 minus your age and call it a day. That formula was never clinically validated and ignores your resting heart rate, the variable that matters most. Calculate My Heart Rate uses the Karvonen method to give you five personalized training zones based on your actual physiology. It also supports the Tanaka, Gulati, Nes, and traditional 220-minus-age formulas so you can compare approaches side by side. A built-in resting heart rate tracker lets you log morning measurements and watch your fitness trend over time. No wearable needed. Free, browser-based, no account required. Your data stays on your device. Built out of frustration with tools that either cost money, overcomplicated everything, or skipped the most important input entirely.