Run Off The Bike Calculator

How to use the result

Use your fresh standalone run pace as the starting point, then let bike intensity, race distance, heat, and nutrition confidence add the fatigue cost. The adjusted pace is the run target to place back into the full race calculator.

• Use standalone 10K pace for Sprint and Olympic planning.
• Use recent half-marathon or long-brick data for 70.3.
• Use conservative long-run or marathon data for Ironman.

Example race read

A runner who can hold 5:00/km fresh might plan 5:20-5:35/km in an Olympic triathlon after a controlled bike, but 5:45-6:15/km in a hot 70.3 if the bike was near the top of the effort range.

Common mistakes

The classic mistake is entering a fresh personal-best run pace and calling it a triathlon run plan. If the bike split requires surging, poor fueling, or high heat cost, the first kilometer out of T2 will expose the fantasy quickly.

When to be conservative

Choose the slower estimate when the bike course is hilly, the run starts in heat, your long bricks fade late, or your nutrition plan is untested. The point is not to predict suffering perfectly; it is to avoid building a plan that needs perfect legs.