Half marathon pace chart

Find your goal finish time in the left column. The next two columns are the average pace you need to hold, per kilometre and per mile. The four columns after that are your checkpoints — the clock time you should see as you pass 5K, 10K, 15K and 20K if you are running an even effort.

Checkpoints are the useful part. Average pace is something you only know afterwards; a split is something you can act on while there is still race left.

These splits assume perfectly even pace, which almost nobody runs and nobody should aim for. The chart is a reference, not an instruction.

In practice the closing 5K of a half marathon is where the race is decided, and arriving there with something left is worth more than any time you bank early. Start 5–10 seconds per kilometre slower than the chart says and take it back over the final third. A negative split feels like a good race; a positive split feels like the wheels coming off, even when the finish time is identical.

The other adjustment is course and conditions. Anything above roughly 15°C, a headwind on an exposed stretch, or meaningful elevation will cost you time no chart can predict. Run the effort, check it against the splits, and adjust — do not chase a number that stopped being realistic at 8K.

The most common mistake is picking a goal from what you would like to run rather than what your training supports. Two sanity checks:

• Recent 10K. A realistic half marathon is roughly your 10K time doubled plus 8–12 minutes, assuming you have done the long runs.
• Long-run pace. Your target half pace should feel comfortably faster than your easy long runs, but not close to your 5K effort. If your goal pace is your current 10K pace, it is too fast.

Once the number is honest, the training matters more than the chart. Holding 5:20/km for 21.1 km is a different capability from holding it for 10 km, and that gap is closed by long runs and tempo work, not by knowing your splits.