Race Shape › Calculators › Two Oceans 21 km time predictor
Two Oceans 21 km · Sunday, 4 April 2027 (expected)Two Oceans 21 km time predictor
The Two Oceans Half is a sea-level half marathon in Cape Town, run on the same weekend as the 56 km ultra. Type your own numbers and get a predicted finish, corrected for the altitude you train at.
| Distance | 21.1 km |
|---|---|
| Race altitude | 30 m |
| Even-pace halfway | 57:39 |
| Your fitness (VDOT) | 38.2 |
Flat-course physiology plus an altitude correction. Hills, heat and pacing are not modelled: allow for the course.
Racing it well
It is not a flat half, so treat the prediction as a ceiling for a good day. Start in your seeding batch, run the first 5 km by feel in the crowd, and race from halfway.
What the prediction includes
Your fitness from the race you type (Daniels’ VDOT), the distance, and the difference in altitude between where you train and the race’s 30 m — about 2% for every 300 m above 500 m. It does not model the hills, heat or your pacing, so allow for the course.
A full 16-week block for the Sunday, 4 April 2027 (expected) race starts on Monday Monday, 7 December 2026. The Two Oceans 21 km training plan page has the calendar and race-day targets.
Build my Two Oceans 21 km plan — free to buildSee your whole block before you pay.
Common questions
How do I predict my Two Oceans 21 km time?
Type a recent race and where you train. The calculator works out your fitness, applies it to the race distance and corrects for altitude.
Is the Two Oceans Half hilly?
It has real climbs and is slower than a flat half. Plan on a little slower than the predicted time unless you have trained on hills.
When is the Two Oceans 21 km?
Sunday, 4 April 2027 (expected). Check the official entry page before booking anything.
When should I start training for the Two Oceans 21 km?
A full 16-week block starts on Monday Monday, 7 December 2026. A plan built later counts back from race day.