Free TDEE, running pace & fitness calculators.
Running
Calculate your running pace, predict race finish times, generate VDOT-based training zones, plan interval sessions, and estimate VO2 max. Tools are built on Jack Daniels' VDOT system, the Riegel race predictor formula, and Cooper's VO2 max test — the same methods used by coaches and competitive runners.
Use our free running pace calculator to find your pace, speed, and finish time for any distance — 5K to marathon.
Use our free running splits calculator to generate per-kilometre and per-mile split times for any race distance and goal pace.
Calculate even or negative splits for any race distance and goal time — perfect for pacing strategy on race day.
Use our free interval training calculator to plan work intervals, rest periods, and total workout duration for any structured session.
Use our free VDOT calculator to estimate your VDOT score and optimal training pace zones from a recent race time.
Use our free race time predictor to forecast your finish time for any distance using a recent race result and the Riegel formula.
Estimate your VO2 max and aerobic fitness category from a timed run with our free VO2 max calculator.
Where to start: use the VDOT Calculator with a recent race time to get your training pace zones, then use the Running Pace Calculator to convert those zones into per-km and per-mile targets for each workout.