Free tools
Running calculators
Twelve calculators for training and racing, free, in your browser, no account. The pace tools run the same Jack Daniels math Shed uses to build your plan. The rest do the arithmetic you would otherwise be doing on the back of an envelope the night before a race.
VDOT Calculator
Turn a race result into your VDOT, training paces, and equivalent times.
OpenRace Time Predictor
Predict your 5K, 10K, half, and marathon from one recent race.
OpenTraining Pace Calculator
Get your easy, marathon, threshold, interval, and rep paces.
OpenHeart Rate Zone Calculator
Five zones from your max, resting, or threshold heart rate.
OpenRace Split Calculator
Even or negative splits for your goal time, mile by mile.
OpenTreadmill Pace Converter
What an incline and belt speed is worth as an outdoor pace.
OpenMarathon Fuel Calculator
Carbs per hour, gels, and fluid for your race time.
OpenSweat Rate Calculator
Weigh in and out of a run to find how much you need to drink.
OpenTaper Calculator
Week-by-week volume for the last three weeks before a race.
OpenWeekly Mileage Planner
A safe build from where you are now to where you need to be.
OpenYasso 800 Calculator
What your 800 repeats say your marathon is worth.
OpenRun Walk Calculator
Finish time and interval ratio for a run-walk race strategy.
Open
Stop calculating. Start training.
These numbers are the first 30 seconds of what Shed does.
Shed reads your Apple Health, grounds your VDOT in your actual training — not one race — and writes the whole block: every workout, every pace, adjusted as life happens. The calculator gives you a snapshot; Shed gives you the plan.
Get your plan on iPhone