Free running tools

Calculators and utilities for half marathon training — all free, no sign-up required.

All free · no sign-up required

Fitness score

VDOT Calculator

Turn any recent race time into your VDOT fitness score, race predictions, and training paces.

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Finish time

Half Marathon Time Predictor

Predict your half marathon finish time from a recent 5K, 10K, or any race effort.

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Intro price · only 100 places left

Build your plan for $19.99

One payment, per race. No subscription to manage and nothing you forgot to cancel — just a plan that adapts to your life until the day you line up.

Build your plan for $19.99

Only 100 places left at the intro price — normally $34.99.

  • Intro price — only 100 places left
  • No subscription, no monthly fees
  • The plan adapts as you train