Karvonen Formula Calculator — Heart Rate Training Zones
Find your target heart rate for any exercise intensity using the Karvonen (Heart Rate Reserve) method. Enter your age, resting heart rate and desired intensity percentage — and see your target bpm alongside all five training zones.
years
bpm
bpm
%
At 70% intensity — Zone 2 — Aerobic base
- 1
Maximum heart rate (Haskell-Fox)
220 − 30 = 190 bpmPopulation-average formula; enter your measured max HR for a more personalised result. - 2
Heart Rate Reserve (HRR)
190 − 65 = 125 bpm - 3
Target heart rate
(125 × 70% ÷ 100) + 65 = 153 bpm
How does this calculator work?
Karvonen target HR = (HRR × Intensity%) + Resting HR, where HRR = Max HR − Resting HR and Max HR ≈ 220 − age. The five zones run 50–100% HRR: Zone 1 (recovery) to Zone 5 (VO₂ max). Personalising with your actual resting HR makes zones more accurate than simple max-HR percentages.
Formula
How this is calculated
The Karvonen formula uses the Heart Rate Reserve (HRR) — the difference between your maximum heart rate and your resting heart rate — to set training zones. This approach is more personalised than the simple percentage-of-maximum-heart-rate method because it factors in your fitness baseline: a well-trained athlete with a low resting heart rate of 45 bpm trains at a very different absolute beat count than a sedentary person with a resting HR of 80 bpm, even if both target "70% intensity".
The formula is: Target HR = (HRR × Intensity%) + Resting HR. Maximum heart rate defaults to 220 − age (Haskell-Fox formula, 1971), which is a population average with a standard deviation of roughly ±10–11 bpm. For a more accurate estimate you can measure your true maximum in a supervised maximal exercise test, or use the Tanaka formula (208 − 0.7 × age, published 2001) — enter either value in the optional "Max HR" field.
The five Karvonen zones correspond to 50–60% (active recovery), 60–70% (aerobic base building), 70–80% (tempo / threshold approach), 80–90% (lactate threshold and above), and 90–100% (VO₂-max and sprint efforts). Training across all zones in the right proportions — typically a polarised 80/20 approach — produces the best long-term endurance adaptations.
Frequently asked questions
The Karvonen method anchors training zones to your Heart Rate Reserve (Max HR − Resting HR) rather than to a raw percentage of Max HR. Because it includes resting HR, it adjusts for individual cardiovascular fitness: a fit athlete with a low resting HR gets higher absolute target beats than an unfit person at the same "percentage" — a more physiologically meaningful prescription.
Measure in the morning immediately after waking, before getting out of bed. Use a finger on your wrist (radial pulse) or neck (carotid pulse), count beats for 60 seconds, and average 3 consecutive days. Resting HR decreases with aerobic fitness — typical ranges: sedentary adult 70–80 bpm, recreational athlete 55–65 bpm, elite endurance athlete 28–45 bpm.
Zone 1 (50–60% HRR) builds aerobic base and aids recovery with very low fatigue. Zone 2 (60–70%) is the classic long-slow-distance zone that develops fat metabolism and mitochondrial density. Zone 3 (70–80%) is tempo work that improves aerobic threshold. Zone 4 (80–90%) stresses the lactate threshold and raises maximal steady-state pace. Zone 5 (90–100%) recruits fast-twitch fibres and raises VO₂ max but is very fatiguing — most athletes spend less than 10% of total training time here.
Also known as
TG we-Calculate Editorial Team. (2026). Karvonen Formula Calculator — Heart Rate Training Zones [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/karvonen-formula-calculator
TG we-Calculate Editorial Team. "Karvonen Formula Calculator — Heart Rate Training Zones." TG we-Calculate. 2026. https://we-calculate.com/calculator/karvonen-formula-calculator.
TG we-Calculate Editorial Team, "Karvonen Formula Calculator — Heart Rate Training Zones," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/karvonen-formula-calculator
@misc{wecalculate_karvonen_formula_calculator, title = {Karvonen Formula Calculator — Heart Rate Training Zones}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/karvonen-formula-calculator}}, year = {2026}, note = {TG we-Calculate} }
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