Beatcast
Heart rate calculators
Updated
Short answer
Four calculators and two zone tools, all running in your browser. Nothing you enter is sent, stored or logged. They use the same formulas as Beatcast, so a result here matches the number in the app for the same inputs.
The tools
- Heart rate zones calculator. Five, three or two zones from your age, a measured maximum, a resting rate or a threshold.
- Zone 2 heart rate calculator. The same engine, opened on zone 2, with four definitions side by side.
- Max heart rate calculator. Four published equations for one age.
- Karvonen formula calculator. Zones from your reserve, with a worked example.
- Heart rate zones by age. A static table for ages 20 to 70.
- Calories burned by heart rate. Active energy from the Keytel 2005 equation.
Which formula Beatcast uses
For maximum heart rate, Tanaka: 208 minus 0.7 times age, unless you enter a measured number. For zones, a share of that maximum, a share of your heart rate reserve if you choose Karvonen, or a share of your threshold. For calories, Keytel 2005, counting active energy only, and only if you switch it on.
Why Tanaka? 220 minus age is the number everyone has heard, and it misses further for older adults. I chose the one that fits the data better, and you can override it.
What an estimate is
Every number on these pages is an estimate. An age-based maximum can be off by roughly a dozen beats for one person. A calorie figure from heart rate is a rough guide for a group and a rougher one for you. Treat the tools as a starting line.
These are training estimates. If you take medication that changes your heart rate or have a heart condition, ask your clinician before using age-based numbers. Beatcast is not a medical device.
Where Beatcast fits
Onboarding asks for your age and builds zones from it, and the sensor screen shows which numbers produced them. Beatcast on the App Store. Fourteen days free, then one purchase. A sensor is required.
New to all this? Start with heart rate on iPhone: start here.
Good to know
Beatcast is not a medical device. It is built for training and general wellbeing, and it cannot detect, diagnose, treat or monitor any condition. If something about your heart worries you, talk to a doctor rather than to an app.
Apple, iPhone and Apple Health are trademarks of Apple Inc. All other names belong to their owners. Beatcast is an independent product and is not affiliated with, endorsed by or certified by any of them.
All calculators
- Heart rate zones calculatorCalculate five, three or two heart rate zones from age, a measured maximum, resting rate or threshold. The same numbers Beatcast builds its zones from.
- Max heart rate calculatorEstimate your maximum heart rate by age with four published equations side by side, plus what an estimate can and cannot tell you.
- Calories burned by heart rate calculatorEstimate active calories from heart rate, weight, age, sex and time with the Keytel equation. An estimate, not a measurement. Runs in your browser.
- Zone 2 heart rate calculatorFind your zone 2 heart rate range by age with four common definitions: percent of max, heart rate reserve, Maffetone's 180 minus age and a lab threshold.
- Karvonen formula calculatorCalculate heart rate zones with the Karvonen formula from your maximum and resting heart rate. The reserve explained, with a worked example and the limits.
- Heart rate zones by ageFive heart rate zones by age, from 20 to 70, as percent of maximum using the Tanaka equation. A static table, with the sentence that a table cannot know you.