Heart Rate Zones Calculator

• Enter age and, if available, resting heart rate.
• If you know your real max heart rate (from a supervised or field test), enter it to override the age-based formula everywhere below.
• Choose Karvonen for personalized zones using heart-rate reserve, or choose a max-HR-only formula.
• Select a fitness goal so the calculator can highlight the best training zone and create a workout plan.
• Use the visual gauge, zone table, talk test, and RPE scale to understand recovery, fat-burning, cardio, hard, and peak effort ranges.

The calculator estimates maximum heart rate from age, then builds training zones from percentage ranges. If you enter a known max heart rate, that value replaces the formula estimate in every downstream calculation — heart-rate reserve, the zone table, the current-HR classification, and the workout plan — since age-based formulas have a typical margin of error of roughly ±10–12 bpm around any individual's true maximum. The Karvonen method separately controls whether zones are built from heart-rate reserve (which adjusts targets based on resting heart rate) or from a plain percentage of max heart rate; that choice applies whether the max HR itself came from a formula or from your own known value.

• Do not treat estimated max heart rate as an exact personal maximum.
• Do not skip warm-up and cool-down when doing higher-intensity training.
• Do not assume “fat-burning zone” means the fastest fat loss; total activity, nutrition, consistency, and recovery matter too.
• Do not use this calculator as medical clearance for exercise, especially if medication, pregnancy, heart conditions, dizziness, chest pain, or exercise restrictions apply.
• Do not rely only on a wrist wearable during HIIT; wrist sensors can lag during rapid intensity changes.

What is the Karvonen method?

The Karvonen method calculates target heart rate from heart-rate reserve, which is maximum heart rate minus resting heart rate. It personalizes zones more than a max-heart-rate-only method.

Which zone is best for fat burning?

Zone 2 is often used for sustainable aerobic work and is commonly called the fat-burning or easy aerobic zone. For body composition goals, overall energy balance and consistency also matter.

Is max heart rate exact?

No. Formulas estimate average max heart rate, typically within about ±10–12 bpm of any individual's true value. Individual max heart rate can vary, so use zones as a guide and pay attention to effort and symptoms. If you have a real tested max heart rate (from a supervised or field test), entering it in the optional "Known max HR" field overrides the formula everywhere in this calculator.

How accurate are wearable heart-rate readings?

Wrist heart-rate sensors can be useful for steady workouts but may lag during HIIT or fast intervals. Chest straps are often better for interval training. Use perceived effort, symptoms, and heart rate together.

Can I use my own known max heart rate instead of a formula?

Yes. The optional "Known max HR" field overrides both the standard and Tanaka formulas for every calculation — heart-rate reserve, the zone table, your current-HR classification, and the workout plan. This matters most for people whose real max heart rate differs meaningfully from their age-based estimate, which is common for trained athletes and older adults who remain highly trained.

Is this a medical tool?

No. It is an educational fitness planning calculator, not medical advice or exercise clearance. Medication, pregnancy, heart conditions, or medical restrictions can change safe exercise targets.