Heart Rate Zone Calculator

2026-10-17

Enter your age to see your estimated maximum heart rate by three common formulas side by side, or type in a measured value. The calculator then splits it into five training zones, optionally with the Karvonen method if you know your resting pulse, and tells you which zone your current pulse is in.

How to use the heart rate zone calculator

1. Type your age. The three formulas in the "Maximum heart rate" card update straight away.
2. Choose which maximum to build the zones on. If you have ever measured your true maximum in a hard test, type it into "Measured max heart rate" and pick "Measured".
3. Optional: enter your resting heart rate, ideally taken in bed right after waking. Then switch the method to Karvonen to base the zones on your heart rate reserve. The table always shows both columns once a resting rate is entered.
4. Read the zone bar and the table. Each zone shows its range in beats per minute (bpm).
5. Optional: enter your current pulse to see which zone it falls in. A marker on the bar and a highlighted table row show the same thing.

How it works

Maximum heart rate (HRmax) is the highest rate your heart can reach during all-out effort. Measuring it needs a hard, ideally supervised, test, so most people use a formula based on age. The calculator shows three, and rounds each to a whole beat:

Classic: HRmax = 220 − age Tanaka: HRmax = 208 − 0.7 × age Gulati: HRmax = 206 − 0.88 × age

The classic rule is the simplest and by far the best known, but it was never fitted carefully to data. The Tanaka formula comes from a 2001 analysis of many studies of healthy adults and is usually closer for people over 40, where the classic rule tends to underestimate. The Gulati formula was derived from a large group of women and gives lower values; this page offers it as an option for women, and it is not chosen automatically. Each formula describes an average. For a single person the real maximum often differs by 10 beats or more in either direction.

Zones are percentages of that maximum. With the % of maximum method:

zone limit = HRmax × percentage

With the Karvonen method the zones are percentages of the heart rate reserve, which is the gap between maximum and resting rate:

target = HRrest + percentage × (HRmax − HRrest)

Here HRrest is your resting heart rate, HRmax is the maximum used, and the percentage is 0.50 for 50%, 0.60 for 60% and so on. Because the resting rate is added back, Karvonen targets are higher than plain percentages of the maximum, and fitter people, who have a lower resting rate, get a wider reserve.

The five zones are 50–60%, 60–70%, 70–80%, 80–90% and 90–100%. A zone starts at its rounded lower limit and ends one beat before the next zone starts, so no pulse value belongs to two zones. A pulse exactly on a boundary counts for the higher zone. Below the lower limit of zone 1 the page says "below zone 1"; above the maximum it says so as well, which usually means the estimated maximum is too low for you.

Examples

Example 1 — the three formulas at age 20. Classic: 220 − 20 = 200. Tanaka: 208 − 0.7 × 20 = 194. Gulati: 206 − 0.88 × 20 = 188.4, shown as 188.

Example 2 — % of maximum, age 45. Tanaka gives 208 − 31.5 = 176.5, rounded to 177. The limits are 50% = 88.5 (89), 60% = 106.2 (106), 70% = 123.9 (124), 80% = 141.6 (142), 90% = 159.3 (159). The zones are therefore 89–105, 106–123, 124–141, 142–158 and 159–177 bpm. A pulse of 140 is in zone 3.

Example 3 — Karvonen, age 45, resting rate 60. With a maximum of 177 the reserve is 177 − 60 = 117. The limits are 60 + 0.5 × 117 = 118.5 (119), 130.2 (130), 141.9 (142), 153.6 (154) and 165.3 (165). The zones are 119–129, 130–141, 142–153, 154–164 and 165–177 bpm. The same pulse of 140 is now in zone 2, because Karvonen zones start higher.

Example 4 — measured maximum. Maximum 185, resting rate 55, reserve 130. Limits: 55 + 65 = 120, 55 + 78 = 133, 55 + 91 = 146, 55 + 104 = 159, 55 + 117 = 172. Zone 3 is therefore 146–158 bpm.

What each zone is for

Intensity is easiest to judge by breathing. In zone 1 and zone 2 you can hold a normal conversation. In zone 3 you speak in short phrases. In zone 4 you manage only a few words, and in zone 5 you cannot talk at all and can keep going for only a short time.

• Zone 1 (50–60%): warm-up, cool-down, recovery days.
• Zone 2 (60–70%): easy aerobic training that builds a base and can be repeated for long sessions.
• Zone 3 (70–80%): steady, moderately hard work such as a brisk run or tempo ride.
• Zone 4 (80–90%): hard efforts near your threshold, usually done in blocks of a few minutes.
• Zone 5 (90–100%): short intervals of under a few minutes with full recovery between them.

Many training plans spend most of their time in zones 1 and 2 and add smaller amounts of zones 4 and 5. These descriptions are general; the right mix depends on your goal, your fitness and your coach or doctor.

Common mistakes

• Treating the formula as a measurement. It is an average for a population. If your pulse regularly goes above your estimated maximum, trust the observation and use a measured value.
• Taking resting rate at the wrong moment. After coffee, stress or a poor night the value is higher. Use the lowest typical value over a few mornings.
• Mixing methods. Percentages of maximum and Karvonen give different numbers for the same zone name. Pick one and keep using it.
• Ignoring conditions that change heart rate. Heat, dehydration, altitude, illness, caffeine and some medicines all move your pulse for a given effort.

Frequently asked questions

Which maximum heart rate formula is most accurate?

None is accurate for every individual. Tanaka fits healthy adults better than the classic rule, especially after 40, but a measured maximum beats any formula.

Should I use the Gulati formula?

It was derived from women and is offered as an option for them. Use it if you want to see how much a women-based estimate differs; the zones follow whichever maximum you select.

What is the difference between Karvonen and % of maximum?

Karvonen starts from your resting rate, so it adapts to your fitness. % of maximum ignores the resting rate. Karvonen zones start at a higher pulse, as in example 3.

Why is my pulse above my calculated maximum?

The estimate is an average and your true maximum may simply be higher. The calculator then reports a pulse above the maximum. A measured value is the fix.

Can I use these zones if I take heart medication or have a heart condition?

Not without medical advice. Medicines such as beta blockers lower the heart rate, so the formulas do not apply. Ask a doctor which range is safe for you.

Is my data sent anywhere?

No. All calculations run in your browser. The values you enter stay in your browser's local storage on this device, so they are still there when you return, and nothing is uploaded.

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