Running & Cycling Calculator
Comprehensive endurance sports calculator combining pace, speed, heart rate zones, calorie burn, VO2 max estimation, race predictions, and split times. For runners and cyclists of all levels.
About this calculator
This calculator merges seven endurance-training tools into one: pace and speed conversion, calorie burn, heart-rate training zones, VO2 max estimation, race-time prediction, and mile-by-mile or kilometer-by-kilometer splits, for both running and cycling. Enter your distance and finish time and it derives your pace per mile and per kilometer, then layers on personal data — age, weight, gender, and resting heart rate — to estimate calories burned and five Karvonen-method heart-rate training zones. Calories burned scales directly with body weight and total time at your current MET (metabolic equivalent) level, so a heavier athlete completing the same workout is calculated to burn more calories even though gender and resting heart rate have no effect on that estimate at all; those two inputs feed only the VO2 max and heart-rate-zone calculations.
VO2 max is estimated from the ratio of your maximum to resting heart rate rather than measured directly in a lab, so treat it as a rough fitness indicator, not a clinical-grade result. Race-time predictions use the Riegel formula (T2 = T1 x (D2/D1)^1.06), which extrapolates reasonably well between nearby distances but grows less reliable the further the target distance sits from what you actually ran — predicting a marathon from a 5K time carries more uncertainty than predicting a 10K from it. Max heart rate defaults to the 220-minus-age formula unless you override it, and that formula is itself a population average with wide individual variation.
Step 1 of 4
How to Use This Calculator
- Select Activity Type (Running or Cycling) and your preferred Unit System.
- Enter the Distance and your finish time (Hours, Minutes, Seconds).
- Input Age, Weight, Gender, and Resting/Max Heart Rate for calorie estimates.
- Choose your Split Display unit (per mile or per kilometer).
- Review your pace, speed, estimated calories, heart rate zones, and predicted race times.
What each input means
- Activity Type
- Choose your activity for appropriate calculations.
- Unit System
- Choose your preferred measurement system.
- Distance
- Total distance covered.
- Hours
- Hours component of total time.
- Minutes
- Minutes component of total time.
- Seconds
- Seconds component of total time.
- Age
- Used for heart rate zones and VO2 max calculation.
- Weight
- Used for calorie calculations.
- Gender
- Used for VO2 max estimation.
- Resting Heart Rate
- Measure in the morning before getting up.
- Max Heart Rate
- Leave at 0 to calculate from age (220 - age).
- Split Display
- How to display split times.
What each result means
- Zone 2 (Aerobic)
- Best for building endurance base.
- Zone 4 (Threshold)
- For improving speed and lactate threshold.
How this is calculated
Worked example, using the default values
- Identify Input Parameters12 parametersActivity Type = 0, Unit System = 0, Distance = 3.1, Hours = 0, Minutes = 25, Seconds = 0, Age = 30, Weight = 150, Gender = 0, Resting Heart Rate = 60, Max Heart Rate = 0, Split Display = 0 = 12 input(s) provided
- Calculate PacePace8:04 = 8:04
- Calculate Calories BurnedCalories Burned298 = 298
- Calculate PacePace5:01 = 5:01
- Calculate SpeedSpeed7.44 = 7.44
Engine last updated . Checked against 1 independently-derived test — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why don't gender and resting heart rate change my calorie burn estimate?
Calories burned depends only on your MET (metabolic equivalent) value at your current speed, your body weight, and total workout time — gender and resting heart rate feed exclusively into the VO2 max estimate and heart-rate training zones, so changing them shifts those numbers without touching the calorie total at all.
How accurate are the race time predictions?
Predictions use the Riegel formula, a well-established endurance-exercise extrapolation that scales your current pace by the ratio of distances raised to the power 1.06. It works best for nearby distances, such as a 10K time predicting a half marathon, and grows less reliable the further apart the distances are, since fatigue and pacing strategy change nonlinearly over longer efforts.
What happens if I don't enter my max heart rate?
Leaving Max Heart Rate at its default of 0 tells the calculator to estimate it using the common 220-minus-age formula. This is a population average that can be off by 10 to 20 beats per minute for any given individual, so if you know your measured max heart rate from a stress test, entering it directly gives more accurate training zones.
Does raising my body weight always raise the calorie estimate?
Yes — calories burned scales directly and proportionally with body weight in this calculator's formula, holding your MET value and workout duration fixed, so a heavier athlete completing an identical route in an identical time is calculated to burn more energy than a lighter one, consistent with how MET-based calorie formulas work in exercise science.
Why do my heart rate training zones shift if I only update resting heart rate?
The five training zones are built from the Karvonen method, which multiplies your heart rate reserve (max heart rate minus resting heart rate) by each zone's percentage band and then adds resting heart rate back. Raising resting heart rate narrows that reserve and shifts every zone boundary upward, even though your max heart rate stays the same.
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Running Pace Calculator
Calculate your running pace per mile and per kilometer. Get predicted race times for 5K, 10K, half marathon, and marathon distances.
Sports, Outdoors & RecreationCycling Speed Calculator
Calculate cycling speed, distance, or time. Includes pace, calorie burn estimates, and metric conversions.
Health & FitnessHeart Rate Zones Calculator
Calculate your personalized heart rate training zones using the Karvonen method. Optimize your cardio workouts for fat burn, endurance, or performance.
Sports, Outdoors & RecreationRunning Splits Calculator
Calculate running pace, splits, and average speed. Track your performance for any distance.
Health & FitnessVO₂ Max Estimate Calculator
Estimate your VO2 max (maximum oxygen consumption) based on heart rate. Assess cardiovascular fitness.
More in Sports, Outdoors & Recreation.