# Heart Rate Calculator (Max, Resting and Training Zones)

URL: https://speedycalculator.com/calculators/sports/heart-rate/
Last updated: 2026-10-30

> The heart rate calculator estimates your maximum heart rate, measures your resting heart rate from a 15-second count, rates it, and gives your heart rate reserve and training zones (Karvonen method).

## Inputs

- Age (years)
- Measured maximum heart rate (0 = estimate)
- Do you know your resting heart rate?
- Resting heart rate (bpm)
- Pulse count in 15 seconds

## Results

- Maximum heart rate
- Resting heart rate
- Resting heart rate rating
- Heart rate reserve
- Zone 1 – Very light (50–60%) from
- up to
- Zone 2 – Light / fat burning (60–70%) from
- up to
- Zone 3 – Moderate / aerobic (70–80%) from
- up to
- Zone 4 – Hard / anaerobic (80–90%) from
- up to
- Zone 5 – Maximum (90–100%) from
- up to

## Formula

```
HRmax = 192 − 0.007 × age² (Gellish) or measured · RHR = 15-s count × 4 · HRR = HRmax − RHR · Target = RHR + % × HRR
```

## Explanation

Your heart rate tells you how hard your body is working. Resting heart rate is a simple fitness marker – well-trained athletes often have 40–60 bpm – and the reserve between resting and maximum sets your training zones.

### How to use the Heart Rate Calculator

- **Age (years)**
- **Measured maximum heart rate (0 = estimate)**
- **Do you know your resting heart rate?**
- **Resting heart rate (bpm)**
- **Pulse count in 15 seconds**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Enter your age (or a measured maximum) and your resting heart rate – or count your pulse for 15 seconds.

### Inputs explained

FieldWhat to enterAge (years)A numberMeasured maximum heart rate (0 = estimate)A numberDo you know your resting heart rate?Choose one: Yes, No – I'll count my pulse for 15 secondsResting heart rate (bpm)A numberPulse count in 15 secondsA number

### What each result means

- **Heart rate reserve** = [Maximum heart rate] - [Resting heart rate]
- **Zone 1 – Very light (50–60%) from** = round([Resting heart rate] + 0.5×[Heart rate reserve])
- **up to** = round([Resting heart rate] + 0.6×[Heart rate reserve])
- **Zone 2 – Light / fat burning (60–70%) from** = round([Resting heart rate] + 0.6×[Heart rate reserve])
- **up to** = round([Resting heart rate] + 0.7×[Heart rate reserve])
- **Zone 3 – Moderate / aerobic (70–80%) from** = round([Resting heart rate] + 0.7×[Heart rate reserve])
- **up to** = round([Resting heart rate] + 0.8×[Heart rate reserve])
- **Zone 4 – Hard / anaerobic (80–90%) from** = round([Resting heart rate] + 0.8×[Heart rate reserve])
- **up to** = round([Resting heart rate] + 0.9×[Heart rate reserve])
- **Zone 5 – Maximum (90–100%) from** = round([Resting heart rate] + 0.9×[Heart rate reserve])
- **up to** = round([Resting heart rate] + 1.0×[Heart rate reserve])

### Example values

How the main result changes when **Age** changes and everything else stays at the example values above:

Age (years)Heart rate reserve (bpm)17.512526.251223511843.7511452.51087093

## Worked example

Inputs — Age (years): 35; Measured maximum heart rate (0 = estimate): 0; Do you know your resting heart rate?: Yes; Resting heart rate (bpm): 65.

Results — Maximum heart rate = 183 bpm; Resting heart rate = 65 bpm; Resting heart rate rating = Normal (60–100 bpm); **Heart rate reserve = 118 bpm**; Zone 1 – Very light (50–60%) from = 124 bpm; up to = 136 bpm; Zone 2 – Light / fat burning (60–70%) from = 136 bpm; up to = 148 bpm; Zone 3 – Moderate / aerobic (70–80%) from = 148 bpm; up to = 160 bpm; Zone 4 – Hard / anaerobic (80–90%) from = 160 bpm; up to = 172 bpm; Zone 5 – Maximum (90–100%) from = 172 bpm; up to = 183 bpm.

## Key terms

- **Heart rate reserve**: HRmax minus resting heart rate.

## FAQ

**What is a normal resting heart rate?**
60–100 bpm for adults; athletes are often lower.

**When should I measure resting heart rate?**
In the morning before getting out of bed.

**Why use heart rate reserve?**
It personalises zones using your resting heart rate.

**Is a low resting heart rate good?**
Usually yes for fit people, but see a doctor if you have dizziness.


## Sources

- [American Heart Association – Target heart rates](https://www.heart.org/en/healthy-living/fitness/fitness-basics/target-heart-rates)
- [ACSM's Guidelines for Exercise Testing and Prescription](https://www.acsm.org/education-resources/books/guidelines-exercise-testing-prescription)