Heart Rate Zone Calculator
Find the heart rate range you should be training in. This calculator estimates your maximum heart rate and splits it into the five standard training zones — from easy recovery work to all-out intervals — using the Karvonen formula with your resting heart rate.
How This Calculator Works
Every zone starts from your maximum heart rate (HRmax). If you have a value from a lab test or a hard field effort, enter it and the calculator will use it directly. Otherwise HRmax is estimated with the classic 220 − age formula.
The zone boundaries come from the Karvonen method, which works from your heart rate reserve (HRR = HRmax − resting heart rate). Each zone's beats per minute equal resting HR + HRR × the zone percentage, which anchors the scale to your actual fitness: a lower resting heart rate shifts every zone down. If you leave resting heart rate blank, the calculator falls back to plain percentages of HRmax.
- Zone 1 · 50–60% — recovery and warm-up. Very easy, barely feels like exercise.
- Zone 2 · 60–70% — endurance base. Conversational pace, where most of your weekly volume belongs.
- Zone 3 · 70–80% — tempo. Comfortably hard, sustainable for roughly an hour.
- Zone 4 · 80–90% — threshold. Hard intervals, think 8–20 minute repeats.
- Zone 5 · 90–100% — maximal. Short sprints and finishing efforts, seconds at a time.
A common mistake is living in zone 3 — too hard to recover from, too easy to drive adaptation. Polarized training keeps easy days in zones 1–2 and saves zones 4–5 for planned hard sessions, as covered in our cardio training guide.
Training in the right zone also decides what you burn: lower zones draw a higher share of energy from fat, while harder zones burn more total calories. Pair this tool with our calories burned calculator and TDEE calculator to match your training to your nutrition.
References & Sources
Frequently Asked Questions
How do I calculate my heart rate zones?
Estimate your max heart rate (220 minus your age, or a measured value), take your resting heart rate first thing in the morning, then apply the Karvonen formula: resting HR + (HRmax − resting HR) × the zone percentage. A 30-year-old with a resting HR of 60 has zone 2 at 138–151 bpm. This calculator does the math for you.
What is zone 2 heart rate training?
Zone 2 is 60–70% of your heart rate reserve — an effort easy enough to hold a conversation. It builds mitochondrial density and aerobic efficiency with minimal recovery cost, which is why coaches prescribe 70–80% of weekly training time in zone 2 for endurance athletes.
Which heart rate zone burns the most fat?
Lower zones burn a higher percentage of calories from fat, but higher zones burn more calories overall, so total fat oxidized per session is often similar or greater at higher intensity. For fat loss, the total calorie deficit matters more than the zone — see our calories burned calculator and TDEE calculator.
Is the 220 minus age formula accurate?
Only roughly — individual max heart rates vary by 10–12 bpm around it. The Tanaka formula (208 − 0.7 × age) fits population data slightly better. The most accurate option is a measured max: the highest heart rate you reach at the end of an all-out 4–8 minute effort, ideally with a chest strap.
Calories Burned Calculator
Estimate how many calories you burn in any activity - from walking and running to burpees, planks, and weight training. This calculator uses MET values from the 2011 Compendium of Physical Activities, the standard reference for exercise energy expenditure.
TDEE Calculator (Daily Calories)
Calculate your Total Daily Energy Expenditure (TDEE) - the number of calories you burn each day. The calculator uses the Mifflin-St Jeor equation for your basal metabolic rate, multiplied by your activity level.
BMI Calculator
Calculate your body mass index (BMI) and see your WHO weight category instantly. BMI is a quick screening tool that compares your weight to your height - this calculator also shows the healthy weight range for your height so you know your target.
