Predict Your 30K Time From a Half marathon

How a Half marathon predicts your 30K

A 30K is a real race in its own right, popular in Europe and across Canada as a late-winter marathon tune-up, and predicting it from a half marathon is a natural step. You are extending your half by about nine kilometers, so the prediction leans on endurance you may still be building toward the marathon distance.

Read the result as a target that depends on your long-run mileage. A half marathon proves strong aerobic fitness, but a 30K asks you to hold a comparable effort for forty-five minutes to an hour longer. If your training already includes runs in the high teens of miles, the predicted 30K is realistic. If not, treat it as a goal to build toward.

Using a 30K as a marathon rehearsal

Many runners race a 30K not for its own sake but as the final hard effort before a marathon, and predicting it from a half helps set a sensible pace. Riegel multiplies your half time by about 1.45 to reach the 30K, adding a realistic slowdown for the extra distance. That gives you a controlled target rather than a flat-out goal.

Because the point of most 30K races is to rehearse marathon pacing and fueling, you may choose to run slightly slower than the prediction, treating it as a long marathon-effort run rather than an all-out race. Either way, the predicted time gives you a clear pace to anchor the effort, and a useful checkpoint on the road to the full distance.

Want every distance at once? The race pace predictor shows your time for the whole range and prints a pace band, and the VDOT calculator turns this race into your training paces.