Half marathon pace chart: finish time to required pace

21.0975 km · 13.1094 mi

Target times and the pace they need

The half marathon sits where pace stops being forgiving and starts being strategic. Over 21.0975 km, a 30-second-per-kilometre mistake in the first 10 km is nearly five minutes by the finish, and unlike a 5K you cannot make it back with one hard kilometre.

How to read the chart

Every row is a finish time; the two pace columns are the average pace it requires, in minutes per kilometre and minutes per mile.

Two useful directions:

• From a goal: find the target time, read across to the pace you must average.
• From a known pace: read across from what you can hold for an hour, then back to the finish time.

The 1:45:00 row is 4:59 per kilometre — the same pace as a 3:30:00 marathon, because 1:45:00 is exactly half of 3:30:00. That kind of doubling is worth doing deliberately: it is the fastest way to sanity-check whether a marathon goal is consistent with a half marathon result. Doubling your half and adding a few minutes is a rule of thumb, not a formula; the actual relationship is on the predictor.

Where the half marathon hurts

The half is long enough for three things a 5K or 10K mostly avoids:

1. Fuel matters a little. Most runners need nothing for a half, but a badly timed breakfast or a hot day changes the second half.
2. The middle third decides it. Pacing errors made at 5 km are usually still recoverable at 10 km and rarely recoverable at 15 km.
3. Average pace hides drift. A half run as 4:50/4:50/5:05/5:15 is the same average as 5:00 throughout. The chart describes the average; only your splits tell you which one you ran.

Target times

The target table below runs from sub-1:20:00 to sub-2:30:00, the round goals half marathon training plans are usually built around. Bands are inclusive: 1:30:00 exactly is inside sub-1:30:00.

Compare the target pace against the pace you currently hold for a 10K. A half marathon target is credible when the required pace is slower than your 10K pace and you can hold it for 60 minutes in training; it is a stretch when the required pace is faster than your 10K pace, because then you would need a half marathon run faster than a shorter race.

Combining the charts

• Use the 5K chart for speed work targets and the marathon chart if the half is a stepping stone.
• The VDOT calculator turns a half marathon result into training paces — in particular the threshold range, which is the one most half marathon plans are actually built on.
• The pace calculator handles distances that are not on any chart, including the exact 21.0975 km if you want the arithmetic rather than a rounded row.

What a second per kilometre costs here

Over a half marathon, small pace differences are amplified. Every second per kilometre is twenty-one seconds of finish time (21.0975 km × 1 s); five seconds per kilometre is 1:45, and ten seconds per kilometre is 3:31. That is why halfway splits matter more at this distance than at 5K or 10K: being five seconds per kilometre ahead at 10 km is nearly a minute of time already banked, and it is nearly always paid back with interest in the last 5 km.

The chart above is therefore best read as a set of per-kilometre targets rather than as a list of finish times. Pick the row that matches your goal, memorise the pace, and use the finish time as the outcome rather than as something to chase kilometre by kilometre.