Running Calculators
Last updated: October 2026
Heart Rate Training Zones Calculator
Calculate your personalised heart rate training zones using the Karvonen heart rate reserve method, which factors in resting heart rate to give zones that actually reflect your cardiovascular fitness.
Marathon Training Calculator
Plan your marathon buildup by calculating a weekly mileage target and ideal training paces from your goal finish time.
Running Cadence & Stride Calculator
Estimates your target running cadence (steps per minute) and stride length based on your height, current pace, and experience level.
Marathon Fueling Calculator
Calculates how many grams of carbohydrates you need during a marathon or long race based on body weight, expected finish time, intensity, and weather.
Training Pace Zones Calculator
Find your easy running pace and Jack Daniels-style training zones (easy, marathon, threshold, interval) from a recent 5K, 10K, half-marathon or marathon time.
Altitude Pace Adjustment
Estimate how much slower your running pace will be at elevation compared to sea level.
Running Power Zone Calculator
Calculate your running power zones from your critical power output and body weight, adjusted for training altitude.
Running Heat Index Calculator
Estimate how much to slow your easy run pace on hot, humid days to maintain equivalent effort and avoid heat illness.
Marathon Taper Calculator
Calculates the recommended weekly training volume for each week of your pre-race taper, scaling down from peak mileage based on your recovery rate, taper length, and race distance.
Running Calorie Calculator
Calculate how many calories you burn on a run based on your weight, distance, pace, and terrain type.
Running Race Equivalency Calculator
Predict your expected finish time at any race distance using a recent race result.
Altitude Running Adjustment Calculator
Estimate how much slower your running pace will be at high altitude compared to sea level.
Pace Calculator
Calculate your running pace per kilometer and per mile, and your speed in km/h and mph, from distance and finish time, with projected 5K to marathon times at that pace.
Training Load Calculator
Quantify your overall training stress each week by combining mileage, intensity, hard workout count, and years of experience.