Set your half marathon goal time. Get the exact pace per km and mile, your 10 km split, a kilometre-by-kilometre race strategy, and Riegel-predicted finish times for every standard distance. How accurate is this?
Your Goal Time
Hours
Minutes
Seconds
Units
Quick Goals
Who Runs This
Your Half Marathon Pace
to finish a half marathon in 2:00:00
Per Mile
9:09
Speed
10.55
km/h
10 km Split
56:53
| Distance | Split | Cumulative | Pace |
|---|---|---|---|
| 5 km | 28:26 | 28:26 | 5:41 |
| 10 km | 28:26 | 56:53 | 5:41 |
| 15 km | 28:26 | 1:25:19 | 5:41 |
| 20 km | 28:26 | 1:53:45 | 5:41 |
| FINISH · 21.1 km | 6:15 | 2:00:00 | 5:41 |
How a 5:41/km half marathon maps to other race distances at the same relative effort.
Coach's note. A 2:00:00 half marathon predicts a 26:05 5K. If your 5K PR is faster than that, you have the leg speed — channel your training into aerobic endurance and long tempo runs.
Avg Pace
5:41
min/km
Avg Pace
9:09
min/mile
Speed
10.55
km/h
400 m Lap
2:17
track pace
Key kilometre targets for a controlled, progressive 2:00 half marathon.
The arc of a great half. Run 5 s/km conservative through km 3 to keep aerobic cost down. Hold even effort km 4–14. From km 15 the race truly begins — that is where your training investment pays out. Anyone can run the first 10 km fast; the fastest half marathoners run the last 7 km the hardest.
The 10 km mark is your truth meter
By 10 km you should feel controlled and breathing steadily. If you are already gasping, you started too fast, the next 11 km will be damage control. If you feel strong, stay disciplined: the temptation to surge here is a trap. Bank that energy for km 15 onward where it pays compound interest.
The dark zone: km 13–17
This is where half marathons fall apart. You are past the early excitement, not yet close enough to the finish to feel the pull. Glycogen starts to thin, legs complain, and pace drifts. This zone is won in training, specifically in long tempo runs where you hold effort through discomfort. Rehearse it mentally every long run. When the dark zone arrives on race day, you will have been there before.
Race-day nutrition is simpler than you think
Sub-90-minute runners rarely need gels, a solid breakfast and well-stocked glycogen stores are enough. From 90–150 minutes, one gel at km 8–10 prevents the late-race dip. Beyond 2:30, two gels spaced 40 min apart are your friend. The only rule that matters: practise this exact protocol on your long training runs. Your gut needs as much training as your legs.
Half marathon pace ≠ threshold pace
Your half marathon race pace sits at roughly 80–88 % of VO₂max, above pure threshold, below all-out 10K effort. It should feel "comfortably hard" from the gun: controlled but not conversational. Many runners train their threshold well but under-practise sustained half-marathon-specific effort. Long progression runs finishing at goal pace are the single best race-specific stimulus you can add.
Taper smart — do not stop
In the final 10 days, cut your volume by 30–40 % but keep your intensity. Most first-timers taper too aggressively and arrive at the start line feeling flat, slow, and nervous. Two or three short sessions at goal pace in the final week will keep your neuromuscular system sharp without accumulating fatigue. Trust the training, taper legs feel heavy because they are recovering, not because you are losing fitness.
Use your 10K time as a reality check
The Riegel formula suggests a half marathon takes roughly 2.09× your 10K time. If your goal half marathon is far faster than that implies, your training block will need to close the gap, not just your race-day courage. Conversely, a recent strong 10K PR is the single best predictor of half marathon potential. Race a 10K two to four weeks out and use this calculator to translate that result into your half marathon goal pace.
To run 2:00 you need to hold 5:41/km (9:09/mi) from the gun to the tape. At that effort you will reach 10 km in 56:53 and each 400 m track lap should take 2:17. The Riegel formula predicts a 4:10:12 full marathon at the same relative effort.
For most recreational runners, even splits with a 5–10 s/km conservative first kilometre is the best execution strategy. Elite runners typically negative-split by 30–90 seconds over the full distance. The biggest mistake is treating the opening 5 km as a warm-up — starting too fast creates an aerobic debt you spend km 13–18 paying back with interest.
Your half marathon pace of 5:41/km sits at roughly 80–88 % of VO₂max — lactate threshold territory. Key training sessions: (1) Tempo runs at 5:53/km for 30–50 min to build sustainable hard-effort fitness. (2) Long progressive runs finishing the last 5 km at goal pace. (3) VO₂max 1 km repeats at 2:08/400 m (faster than race pace). Do not run every session at race pace — reserve that stimulus for your sharpest workouts each week.
Global averages sit around 2:05–2:15 for men and 2:20–2:35 for women, though this varies considerably by race size, terrain, and country. A common benchmark: sub-2:00 for men under 40 and sub-2:20 for women is broadly considered 'good for age'. If this is your first half marathon, finishing under 2:30 places you comfortably in the mainstream field.
Sub-90-minute runners can typically finish on pre-race nutrition alone. Between 90–150 minutes, one gel taken at km 8–10 provides a useful top-up and helps delay the glycogen dip in the final third. Beyond 150 minutes (2:30+), two gels spaced 40–45 minutes apart are recommended. Always practise your exact nutrition strategy on long training runs at race effort — never test a new product on race day.