Heart Rate Calculator - Max HR, Resting & Karvonen

A heart rate calculator turns four numbers you can measure at home into a complete training picture. Enter your age to estimate your maximum heart rate, your resting pulse to classify cardiovascular fitness, the beats you counted over a short window to get a measured BPM, and your target training intensity to find the Karvonen zone you should be working in.

• • Estimate max heart rate: Use your age to get the Haskell-Fox (220 minus age) and the Tanaka (208 minus 0.7 times age) max heart rate estimates side by side.
• • Classify resting pulse: Compare a morning resting pulse to the American Heart Association normal band of 60 to 100 BPM to spot unusually low or high values.
• • Measure pulse manually: Convert the beats you count at your wrist or neck in 10, 15, 30, or 60 seconds into an accurate beats per minute reading.
• • Plan a training zone: Pick a training intensity between 50% and 100% of heart rate reserve and read off a Karvonen target BPM for steady cardio or interval work.

This tool is most useful when you already know roughly what you want to do with the number. A runner planning long easy miles needs a different number than a cyclist doing intervals, and someone tracking recovery only needs a resting pulse reading. Measure resting pulse before you get out of bed, count beats for the full window without stopping early, and use the age you will be on the day of the workout.

If you only need the zone bands without the manual count step, Target Heart Rate Calculator goes straight to a focused zone tool.

The tool runs three independent formulas and a Karvonen target in a single pass. Each formula takes a different subset of your inputs so the result panel can show all six outputs at once.

• Age: Whole years of age used for both max heart rate formulas.
• Resting heart rate: Pulse in beats per minute measured first thing in the morning.
• Measured beats: Heartbeats counted during the chosen pulse window.
• Pulse window: How long you counted beats: 10, 15, 30, or 60 seconds.
• Training intensity: Percent of heart rate reserve (50-100%) used in the Karvonen formula.

The order of operations is deliberate. Measured BPM comes first because it has no dependency on age or resting pulse. The two max heart rate estimates come next, followed by the heart rate reserve. The Karvonen target is calculated last so it always uses the freshest HRR and intensity values.

Max heart rate is rounded to whole BPM because heart rate is usually reported that way in training plans and on watch screens. The intensity slider is clamped to 50-100% because values outside that band are not used as training zones.

According to Tanaka, Monahan and Seals (2001), Journal of the American College of Cardiology, maximum heart rate is more accurately predicted by 208 minus 0.7 times age than by 220 minus age.

For a deeper dive into how HRR and intensity combine, Karvonen Formula Calculator walks through the formula.

Four ideas explain every result the tool returns.

These four concepts are layers of the same picture: max heart rate sets the ceiling, resting heart rate sets the floor, heart rate reserve is the distance between them, and the Karvonen target is a single point along that line. Consistency in how you measure matters more than the formula itself.

If you want to connect your heart rate reserve to aerobic capacity, VO2 Max Calculator estimates VO2 max from your resting pulse.

Five quick steps turn a few home measurements into a complete training picture.

1. 1 Enter your age: Type your age in whole years. Use the age you will be on the day of the workout, not your birth year.
2. 2 Measure resting heart rate: Take your pulse first thing in the morning for 60 seconds, or use a wearable's morning reading. This is the floor of your heart rate reserve.
3. 3 Count beats over a short window: Place two fingers on your wrist or neck, start a timer, and count beats for 10, 15, 30, or 60 seconds. Enter the count and pick the matching window.
4. 4 Pick a training intensity: Choose 50% for recovery, 60-70% for easy aerobic work, 70-80% for moderate cardio, 80-90% for threshold, and 90-100% for maximum intervals.
5. 5 Read the result panel: Read max heart rate, measured BPM, resting pulse class, heart rate reserve, and Karvonen target at a glance. Use the target as the BPM you should hold on a watch.

On a recovery day, set intensity to 55%. If the Karvonen target is 128 BPM, that is the ceiling; if your watch shows 140 BPM, you are working too hard. At the other end, a 90% target of 170 BPM is the floor for intervals, and dropping below it means the work interval was not hard enough.

Pair the Karvonen target with a goal pace on easy days, and Running Pace Race Split Calculator turns the BPM into minutes per mile or kilometer.

This tool pays off when you stop guessing and start training to a number.

• • Train in the right zone: Anchor each session to a Karvonen target BPM that matches the goal of the day, instead of using RPE alone.
• • Track fitness with resting pulse: Watch your resting heart rate drift down over weeks of training, a quiet signal that aerobic fitness is improving.
• • Spot unusual readings early: An elevated resting pulse class or a measured BPM way above the Karvonen target is a fast signal to rest, hydrate, or get a checkup.
• • Plan intervals without a coach: Use intensity 85-95% for intervals and 50-65% for recovery so each set has a defensible BPM.
• • Convert manual pulse counts: Turn a 10, 15, 30, or 60 second count into exact BPM without the math in your head.
• • Compare two max HR formulas: See the Haskell-Fox and Tanaka estimates side by side, especially as you approach your 40s and beyond.

The biggest payoff is a measurable goal. Instead of "run easy" you have "stay at or below 138 BPM", and instead of "go hard" you have "hold 170 BPM for 3 minutes". Logging your morning resting pulse turns the AHA's 60 to 100 BPM band into a personal trend line that flags stress, illness, or under-fueling before any other metric moves.

Once you have a Karvonen target and a session length, Calories Burned by Heart Rate Calculator estimates the calories burned at that average BPM.

The calculator is deterministic: same inputs, same outputs. What changes the result is what you put in.

• • Max heart rate is estimated from age, not measured. The most accurate max HR comes from a graded exercise test in a lab or a careful field test, not a formula.
• • The Karvonen formula assumes a linear HRR to effort relationship, but real effort is non-linear, especially above 80% of HRR.
• • A resting pulse outside 60-100 BPM does not diagnose a condition. The calculator flags the band but does not replace medical advice.

These factors do not make the tool wrong; they make it a tool, not a verdict. Keep the inputs consistent so outputs are comparable across days. If you are managing a condition, training for a major event, or taking medication that affects heart rate, your clinician or coach can adjust the resting pulse, the max HR estimate, or the intensity bands to match your situation.

According to American Heart Association, a normal resting heart rate for adults ranges from 60 to 100 BPM.

According to U.S. Centers for Disease Control and Prevention, physical activity intensity affects heart rate and breathing, and you can find your heart rate by counting pulse beats and multiplying by the matching factor.

If the home reading keeps looking noisy, ECG Heart Rate Calculator gives a medical-grade rate from an ECG strip using the 300, 1500, and six-second methods.