Free tools
Running calculators
The same Jack Daniels math Shed runs to build your training — free, in your browser, no account. Turn one recent race into your fitness, your paces, and what you could run at every distance.
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.
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