Sports Calculators
Heart Rate Zones Calculator
Calculate non-overlapping percent-max or heart-rate-reserve intensity bands.
Updated
Intensity-band inputs
Calculate heart rate intensity bands
Select one method. The calculator uses an entered maximum heart rate and does not infer one from age.
Whole numbers from 80 through 230.
Need an age-predicted planning value? The Max Heart Rate Calculator provides an estimate, not a measured maximum.
Choose a method, enter the required heart rates, and calculate.
Five non-overlapping bands and their exact thresholds will appear here.
What the bands estimate
The five bands partition an entered heart-rate range using published percentage thresholds. They are neutral intensity intervals, not labels for fuel use, safety, or the best workout for an individual.
Percent-max and HRR
Percent-max multiplies the entered maximum by each threshold. Heart-rate reserve applies each threshold between resting and maximum heart rate, so it requires both values.
Worked examples
At 190 BPM maximum, the 57% threshold is ceil(190 x 0.57) = 109 BPM. With 60 BPM resting, the 30% HRR threshold is ceil(60 + 0.30 x (190 - 60)) = 99 BPM.
Estimated versus measured maximum
Entered maximum heart rate may come from a measurement or a separate estimate. A laboratory-measured maximum is not interchangeable with an age-predicted value.
Common mistakes
Avoid mixing methods, entering a resting value that is not below maximum, treating rounded thresholds as physiological cutoffs, or assuming a device reading is exact.
Training context
For additional educational context, read the heart-rate training guide.
Limitations
These results are population-based planning estimates. Heart-rate intensity bands are not medical measurements or personalized exercise prescriptions. Medication, health conditions, fitness, heat, altitude, stress, sleep, and device accuracy can affect heart rate. This tool does not diagnose fitness, cardiovascular health, or whether exercise is safe for you.
Quick answers
What this calculator answers
- Two separate methods: Percent-max applies thresholds to maximum heart rate. HRR applies thresholds between resting and maximum heart rate.
- No age estimate inside this tool: Enter a measured or selected maximum, or use the separate age-prediction calculator for an estimate. Estimate maximum heart rate
- Boundary policy: Thresholds round upward, and each middle band ends one BPM before the next begins.
Transparency note
Accuracy and limitations
Calzivo tools are built for practical estimates, conversions, and checks. Some tools use standard formulas or simplified assumptions, and results can be affected by input accuracy, rounding, units, local rules, or changing official requirements.
Results depend on the values you enter and any simplified assumptions used by the tool. Verify important results before making decisions or submitting official information.
Reference check
Sources and references
These references provide background context for the topic. They do not replace official advice or documents for personal decisions.
- The effects of training on heart rate
Karvonen, Kentala and Mustala; Annales Medicinae Experimentalis et Biologiae Fenniae, 1957
- Quantity and quality of exercise for developing and maintaining fitness
American College of Sports Medicine Position Stand, 2011; DOI 10.1249/MSS.0b013e318213fefb
- Physical Activity and Exercise Intensity Terminology
ACSM/ESSA Expert and Consensus Statement, 2025
- Target Heart Rates Chart
American Heart Association
- Measuring Physical Activity Intensity
Centers for Disease Control and Prevention
How to Use This Tool
Use these steps to enter the right inputs and interpret the result correctly.
Choose percent of maximum heart rate or heart-rate reserve.
Enter a whole-number maximum heart rate from 80 through 230 BPM.
For heart-rate reserve, also enter a resting heart rate from 30 through 120 BPM.
Calculate and review the five non-overlapping integer BPM bands.
Related Tools
Use Max Heart Rate for an age-predicted planning input, Pace Calculator for running pace, or Race Predictor for an equivalent-time estimate.
Max Heart Rate Calculator
Estimate maximum heart rate from age with the Tanaka equation and clear limitations.
Pace Calculator
Calculate pace, finish time, or distance with explicit kilometre and mile units.
Race Predictor
Estimate one equivalent race time from a known result using the Riegel model.
Related Guides
Background reading and explanations related to Heart Rate Zones Calculator.
Frequently Asked Questions
Common questions about Heart Rate Zones Calculator and how to read the result.
Which intensity-band methods are available?
Choose either percentage of maximum heart rate or heart-rate reserve. The calculator does not combine the methods.
Does this calculator estimate maximum heart rate from age?
No. Maximum heart rate must be entered. The linked Max Heart Rate Calculator provides an age-predicted estimate, not a measured value.
Why does heart-rate reserve require resting heart rate?
HRR applies each percentage to the difference between maximum and resting heart rate, then adds resting heart rate back.
Why do adjacent ranges not overlap?
Each threshold is rounded upward and the preceding band ends one BPM below the next band. That assigns every displayed integer BPM to one band.
Are these personalized exercise prescriptions?
No. They are population-based planning estimates, not medical measurements or personalized prescriptions.