Target Heart Rate Calculator

Your target heart rate during exercise is about 50% to 85% of your maximum heart rate, and your maximum is estimated as 220 minus your age (MedlinePlus). A target heart rate calculator, also called a heart rate zone calculator, does the math for you: at age 35 the maximum is 185 bpm, so the target zone is 93 to 157 bpm. The CDC's narrower bands put moderate activity at 64% to 76% (118 to 141 bpm at 35) and vigorous activity at 77% to 93% (142 to 172 bpm).

Heart rate tells you how hard a session is. For the energy side of training, use the Calories Burned Calculator for a workout, the TDEE Calculator for your full daily burn, and the VO2 Max Calculator to estimate your aerobic fitness.

The target heart rate formulas

Intensity is a percentage written as a decimal, for example 0.70 for 70%. The first two lines are the percentage-of-maximum method that the CDC and MedlinePlus ranges use. The Karvonen method, from a 1957 study by Karvonen and colleagues, applies the intensity to your heart-rate reserve, the gap between your maximum and your resting pulse, and then adds the resting pulse back. That makes the target depend on your fitness as well as your age.

Two federal ranges: MedlinePlus and the CDC

U.S. government health sites describe target heart rate in two slightly different ways, both based on 220 minus age:

• MedlinePlus (National Library of Medicine): a target heart rate of about 50% to 85% of your maximum, with 50% to 70% for moderate exercise and 70% to 85% for vigorous exercise. Beginners aim for the lower number and work up as they get fitter.
• CDC (archived guidance): 64% to 76% of maximum for moderate-intensity activity and 77% to 93% for vigorous activity, citing the American College of Sports Medicine.

The calculator's headline uses the MedlinePlus range and shows the CDC bands underneath. The CDC today describes intensity mostly with the talk test and METs: during moderate activity you can talk but not sing, and during vigorous activity you cannot say more than a few words without pausing for a breath.

Target heart rate chart by age

Maximum heart rate is 220 − age; each range is that maximum times the percentages, rounded to the nearest beat. The 50% to 85% column matches the MedlinePlus table.

Beats per minute. Example from the CDC's guidance: a 50-year-old (maximum 170 bpm) exercising at moderate intensity aims for 109 to 129 bpm.

The five training zones

Fitness watches usually split 50% to 100% of maximum heart rate into five zones. This is a training convention rather than an official standard, and brands draw the lines a little differently, but the common version looks like this:

• Zone 1, very light (50% to 60%): warm-up, cool-down and active recovery.
• Zone 2, light (60% to 70%): easy, conversational endurance work, often marketed as the fat-burning zone.
• Zone 3, moderate (70% to 80%): steady aerobic training that feels comfortably hard.
• Zone 4, hard (80% to 90%): tempo and threshold efforts you can hold for a limited time.
• Zone 5, maximum (90% to 100%): short all-out intervals.

For general health, most of your weekly minutes can sit in the moderate range. The CDC recommends at least 150 minutes of moderate-intensity activity such as brisk walking, or 75 minutes of vigorous activity, every week, plus muscle-strengthening activity on at least 2 days.

Worked example: a 35-year-old, step by step

Age 35, resting heart rate 65 bpm (the calculator's default). Maximum heart rate = 220 − 35 = 185 bpm, and heart-rate reserve = 185 − 65 = 120 bpm. Each row shows both methods:

The overall 50% to 85% target is 93 to 157 bpm by %max and 125 to 167 bpm by Karvonen. The Karvonen targets are higher because the resting rate is added back on top of the reserve.

%max vs Karvonen: how resting heart rate shifts the zones

Same age, different resting pulse. This table holds a 40-year-old (maximum 180 bpm) fixed and varies the resting rate. The %max columns never move; only the Karvonen targets respond to fitness.

A second worked example: a fitter 50-year-old

A 50-year-old runner has a resting heart rate of 50 bpm. The estimated maximum is 220 − 50 = 170 bpm. By the percentage-of-maximum method, Zone 2 (60% to 70%) is 102 to 119 bpm. By the Karvonen method, (170 − 50) × 0.60 + 50 = 122 and (170 − 50) × 0.70 + 50 = 134, so the same zone becomes 122 to 134 bpm. A fit runner who trains by plain %max may therefore be working easier than intended, which is why entering a carefully measured resting rate is worthwhile.

Other formulas for maximum heart rate

The 220 − age formula is the one federal health sites use, but it is a rough average. Tanaka, Monahan and Seals pooled data on 18,712 people from 351 studies and then tested the result in 514 healthy adults. They found that 208 − 0.7 × age fit better, that it was the same for men and women and for active and sedentary people, and that 220 − age underestimates maximum heart rate in older adults. At age 60, Tanaka gives 166 bpm versus 160 bpm. For women, the St. James Women Take Heart Project followed 5,437 women and found an average peak heart rate of 206 − 0.88 × age, below the classic estimate (Gulati et al., 2010). Every formula describes an average, and an individual's true maximum can be well above or below it; only a supervised graded exercise test measures it.

How to use this calculator

1. Enter your age. It sets your estimated maximum heart rate.
2. Pick a formula. 220 − age matches the CDC and MedlinePlus numbers; Tanaka is an alternative that fits older adults better.
3. Add your resting heart rate (optional). Count your pulse for a full minute after waking, before you get up. This adds the Karvonen column.
4. Read the result. The headline is your 50% to 85% target zone. Below it are your maximum, the CDC moderate and vigorous ranges and the five zones.

The result updates as you type, so you can see how much your zones move with a different resting rate.

Who this calculator is for

• New exercisers who want a safe, moderate range instead of guessing how hard to push.
• Runners and cyclists planning easy days, tempo work and intervals by zone, often with the Pace Calculator.
• People with a fitness watch who want to check the zones their device assigns.
• Anyone working toward 150 minutes a week who wants to confirm that their walks count as moderate activity.

Using effort alongside the numbers

Heart rate zones work best together with how the effort feels. On the Borg rating of perceived exertion, a 6-to-20 scale, the CDC's archived guidance noted that your rating times 10 roughly approximates your heart rate during activity, so a rating of 13 ("somewhat hard") corresponds to about 130 bpm, and it described ratings of 12 to 14 as moderate intensity. The talk test is simpler still: if you can talk but not sing, you are working at a moderate level. Perceived exertion is also the better guide for people who take medicines that affect heart rate.

Factors that change your real heart rate

• Heat and humidity: the heart works harder to cool the body, raising the rate at the same pace.
• Hydration: when you are dehydrated, the heart beats faster to keep blood moving.
• Caffeine and stimulants: coffee or pre-workout drinks can raise both resting and exercise heart rate.
• Sleep, stress and illness: all can push your baseline up, so easy efforts read higher.
• Altitude: thinner air makes the heart beat faster to deliver the same oxygen.
• Medications: MedlinePlus notes that some blood pressure medicines lower your heart rate; if you take them, ask your provider what range is healthy.

How to lower your resting heart rate over time

MedlinePlus lists 60 to 100 bpm as a normal resting heart rate for adults and 40 to 60 bpm for well-trained athletes. Regular aerobic exercise is the main habit that brings a resting rate down over weeks and months; sleep, stress and caffeine affect it from day to day. As your resting rate falls, re-run the calculator so your Karvonen targets keep up with your fitness. A resting rate that is persistently above or below the normal range is worth discussing with a doctor.

Limitations and assumptions

• Maximum heart rate comes from an age-based formula, which describes an average; your true maximum may differ.
• It does not account for medications, heart conditions, pregnancy or other clinical factors that change safe ranges.
• The five-zone model is a training convention; the CDC and MedlinePlus ranges are the federal reference points.
• Heat, altitude, illness and dehydration are not modeled.
• Zones are guides. If an effort feels far too easy or impossibly hard, trust how you feel and recheck your inputs.

Sources

• MedlinePlus, U.S. National Library of Medicine: Give your heart a workout (50% to 85% target, 220 − age, age table; reviewed April 2026) and Pulse (normal resting heart rates).
• Centers for Disease Control and Prevention (CDC): Target Heart Rate and Estimated Maximum Heart Rate (archived copy, last reviewed June 2022; 64% to 76% and 77% to 93%) and Perceived Exertion (archived copy; Borg scale).
• CDC: How to Measure Physical Activity Intensity (talk test, METs) and Adult Activity: An Overview (150 minutes a week).
• Tanaka H, Monahan KD, Seals DR (2001), Age-predicted maximal heart rate revisited: PubMed 11153730; Gulati M et al. (2010), heart rate response to exercise in women: PubMed 20585008; Karvonen MJ et al. (1957): PubMed 13470504.
• Herrmann SD et al. (2024), 2024 Adult Compendium of Physical Activities: PubMed 38242596.