What pace do I need for a 21:00 5K?

A 21:00 5K is 4:12/km (6:46/mi), 14.3 km/h, held for the whole race.

What treadmill speed is 21:00 5K pace?

Set the treadmill to 14.3 km/h or 8.9 mph to run 4:12/km (6:46/mi).

Where should I be at halfway in a 21:00 5K?

With even pacing you pass halfway in 10:30; with a negative split, a little later.

What does a 21:00 5K predict for other distances?

The Riegel formula estimates 43:47 for the 10K, 1:12:30 for the 10-mile race, 1:36:36 for the half marathon, 3:21:25 for the marathon, assuming you’ve trained for each distance.

21:00 5K pace

A 21:00 5K is 4:12/km (6:46/mi), 14.3 km/h.

5K finish times around your target, in 10 seconds steps
Change	Time	Pace
−0:40	20:20	4:046:33
−0:30	20:30	4:066:36
−0:20	20:40	4:086:39
−0:10	20:50	4:106:42
Your target Finish time Pace /km
+0:10	21:10	4:146:49
+0:20	21:20	4:166:52
+0:30	21:30	4:186:55
+0:40	21:40	4:206:58

min/kmmin/mikm/hmph

Arrow keys nudge the value. Hold Shift for bigger steps.

Finish times at 4:12 per km

Finish time at this pace for each distance
Distance	Finish time
1K	4:12
1 mile	6:46
5K	21:00
10K	42:00
10 miles	1:07:36
Half marathon	1:28:37
Marathon	2:57:13
50K	3:30:00

Splits for a 21:00 5K

Negative splitEven pace all the way

Splits per km
km	Split	Elapsed
1	4:12	4:12
2	4:12	8:24
3	4:12	12:36
4	4:12	16:48
5	4:12	21:00

Splits per mile
Mile	Split	Elapsed
1	6:46	6:46
2	6:46	13:31
3	6:46	20:17
Final 0.107 mi	0:43	21:00

What a 21:00 5K predicts

Estimate

Estimated times at other distances (Riegel formula)
Distance	Estimated time
10K	43:47
10 miles	1:12:30
Half marathon	1:36:36
Marathon	3:21:25

These are estimates from the Riegel formula, T2 = T1 × (D2 ÷ D1)^1.06. They assume you’ve trained for the other distance, so treat them as a guide, not a promise.

From 20 to 25 minutes, the first kilometre sets it up

Start on goal pace, not faster. The first kilometre of a 5K feels easier than it is.

Two or three runs a week, one with short fast efforts, and a regular timed 5K will move you through this band.

Use the ladder to pick a target: in this band, 30 seconds off your 5K is only a few seconds per km.

Pace questions runners ask

What pace do I need for a 21:00 5K?: A 21:00 5K is 4:12/km (6:46/mi), 14.3 km/h, held for the whole race.
What treadmill speed is 21:00 5K pace?: Set the treadmill to 14.3 km/h or 8.9 mph to run 4:12/km (6:46/mi).
Where should I be at halfway in a 21:00 5K?: With even pacing you pass halfway in 10:30; with a negative split, a little later.
What does a 21:00 5K predict for other distances?: The Riegel formula estimates 43:47 for the 10K, 1:12:30 for the 10-mile race, 1:36:36 for the half marathon, 3:21:25 for the marathon, assuming you’ve trained for each distance.