Run calculator
All calculators for runners in one place: from the pace calculator to split times, heart rate zones and GPX route planning. Every running tool is free, works right in your browser and is built for phone and desktop.
Calculators for runners
Pace calculator
The classic: from distance and time it works out your pace per mile or kilometer and your speed, from distance and pace your finish time. It also lists your times for 5K, 10K, half marathon and marathon. Ideal for training plans and race time predictions.
Pace per km calculator
The same calculation as the pace calculator, but with kilometers as the default unit. You get your pace in minutes per kilometer and your speed in km/h. Handy for races outside the US and for watches that measure in kilometers.
Pace converter
Converts your pace from minutes per kilometer to minutes per mile and back, and speed between km/h and mph. It also shows your times for the common race distances in both units. Useful when a training plan or race uses a different unit than your watch.
Split time calculator
Calculates your split times per mile, kilometer or custom distance for a given finish time. Run even splits or pick a pace profile with a faster start or a faster finish. That way you know your target time at every marker on race day.
Pace chart
Look it up instead of calculating: for every pace in one-second steps, the chart lists the finish times for 5K, 10K, half marathon and marathon. Pick a pace range, for example 8:00 to 8:59 min/mi, and find your time at a glance. A quick reference before race day.
Heart rate calculator
Works out your maximum heart rate and from it your five training zones, from the Health Zone to the Maximum Zone. Choose between the rule of thumb (220 minus age) and the methods of Sally Edwards and Winfried Spanaus. Train at the right intensity.
GPX pace calculator
Upload your route as a GPX file and plan your pace for every section. The calculator takes the elevation profile and, optionally, wind direction and wind speed into account and spreads your finish time realistically over the course. Ideal for races with climbs and descents.
Triathlon calculator
Pick a distance from sprint to Ironman, enter your swim, bike and run speeds plus transition times, and get your finish time. Each leg is shown separately, so you can see where you could gain time.
More calculators
Useful for runners too: body weight, swimming and cycling.
BMI calculator
Calculates your body mass index from weight and height and places the result in the usual categories. A rough guide that does not account for body composition or fitness.
Swim pace calculator
Works out your swim pace per 100 meters from distance and time, or your finish time from a pace. Handy for pool training and for preparing the swim leg of a triathlon.
Bike GPX calculator
Like the GPX pace calculator, but for cycling: upload a GPX file, choose a target time and plan your speed for each section, adjusted for elevation profile, wind direction and wind speed.