Live
Body Fat Calculator
Estimate body fat percentage with the US Navy tape-measure method, plus fat mass, lean mass and your ACE category.
Max Heart Rate Calculator
Estimate your maximum heart rate by age with three formulas and see your heart-rate training zones, including Karvonen zones.
Did we solve your problem today?
How to use this calculator
Enter your values. The result updates as you type; press Calculate to confirm and jump to the result on mobile. Use Share to send the calculator with your result.
Max heart rate formulas
Fox: HRmax = 220 − age
Tanaka: HRmax = 208 − 0.7 × age
Gellish: HRmax = 207 − 0.7 × age
Tanaka, Monahan & Seals (2001) found 220 − age underestimates max heart rate in older adults; their formula fits better across ages. At age 40 all three give about 180 bpm; at 60, Fox gives 160 and Tanaka 166.
Karvonen method
target HR = resting HR + (HRmax − resting HR) × intensity %
Using heart-rate reserve accounts for fitness: a lower resting heart rate shifts zones up. Measure resting heart rate in bed after waking, averaged over a few mornings.
What the zones are for
- Zone 2: easy aerobic base, conversational pace.
- Zone 3: steady tempo efforts.
- Zone 4: threshold intervals.
- Zone 5: short, all-out efforts.
The CDC describes moderate-intensity activity as about 64–76% of max heart rate and vigorous as 77–93%.
Frequently asked questions
What is my max heart rate?
A quick estimate is 220 minus your age; Tanaka’s 208 − 0.7 × age is more accurate for older adults.
What is a dangerous heart rate during exercise?
Repeatedly going above your estimated max, or any chest pain, dizziness or breathlessness out of proportion, needs medical attention.
About this tool
- Written by
- [Author: to be assigned]
- Reviewed by
- Expert review pending
- Last updated
- 31 Oct 2026
See our methodology and editorial policy. Think something’s off? Report an error with this tool.
Related tools
All Health & FitnessLive
Calorie (TDEE) Calculator
Estimate your daily calorie needs (BMR and TDEE) with the Mifflin-St Jeor equation, plus targets to lose or gain weight.
Live
Macro Calculator
Turn your calorie target into daily grams of protein, carbohydrate and fat for your goal and preferred macro split.
Live
BMI Calculator
Calculate adult body mass index (BMI) from height and weight, with the CDC weight category and healthy weight range.
Live
Body Shape Calculator
Find your body shape from bust, waist and hip measurements, plus your waist-to-hip and waist-to-height ratios.
Live
Protein Intake Calculator
Find how much protein you need per day from your body weight and activity, with the RDA and sports-nutrition ranges.