What pace do I need for a sub-25 5K?

Five minutes per kilometre, which is 8:03 per mile or 2:00 for each lap of a 400 metre track. Sub-30 needs 6:00 per kilometre, sub-22 needs 4:24, and sub-20 needs 4:00 flat. Those are averages across the whole race, so a plan that starts slightly slower and finishes slightly faster still hits the same total.

How many laps is a 5K on a track?

Twelve and a half laps of a standard 400 metre outdoor track. Because of the half, the start is 200 metres before the finish line — on the back straight rather than at the usual start-finish position — and you cross the line twelve times before the thirteenth crossing ends the race. On a 200 metre indoor track it is 25 laps, which is why indoor 5Ks are comparatively rare.

Should I run even splits or a negative split?

A slight negative split for almost everyone. Going out fast feels effortless in the first kilometre and is repaid with interest in the last, because the early effort raises blood lactate sooner than it needs to and you spend the rest of the race managing it. Starting five to ten seconds per kilometre slower than target costs very little and usually buys back more than it spends.

Why do the splits still add up when I change the progression?

Because the plan is symmetric about the average. The five kilometre paces are the average plus twice the step, plus the step, the average itself, minus the step, and minus twice the step. The additions and subtractions cancel exactly, so the total is five times the average — your target — no matter how aggressive the progression is. That is why you can experiment freely without recalculating anything.

Is a treadmill 5K the same as a road 5K?

Usually a little easier, though the size of the difference is argued about. There is no air resistance, the surface gives back some energy, and the belt is doing part of the work of bringing your foot back underneath you. Many runners set a one percent incline to compensate, which comes from a much-cited study on the metabolic cost of outdoor running — it is a reasonable approximation at faster paces and probably overcorrects at slower ones.

How much faster should my last kilometre be?

Enough to know you finished on empty, not so much that you left time on the course. With a five second progression the last kilometre is twenty seconds faster than the first, which is a noticeable lift without being reckless. If you finish with a great deal left, the target was conservative; if you fade badly in the fourth kilometre, you started too hard. The fifth kilometre is where the plan is judged.

How do I convert 5K pace to other distances?

Not by holding the same pace — that is the whole difficulty. Pace degrades as distance grows, by roughly four percent per doubling, so a 5K pace cannot be held over 10K and certainly not over a marathon. The general running pace calculator applies Riegel's model to make that conversion properly. As a rough feel, a 20:00 5K corresponds to about a 41:42 10K and a 3:11 marathon for someone with the endurance base to match.

Does the first kilometre really matter that much?

More than any other. A 5K is short enough that the effort is close to your limit throughout, so there is very little margin to absorb a mistake. Going ten seconds too fast in the first kilometre typically costs more than ten seconds later, because the physiological price compounds. It is the one kilometre where discipline pays a measurable dividend, and the one runners most often get wrong in the excitement of a start line.

What is a good 5K time?

Entirely dependent on age, training and background, and a single benchmark is rarely useful. For rough context, many recreational runners finish between 25 and 35 minutes, regular club runners between 18 and 22, and the elite range is under 14. Far more informative is your own trajectory — the same course getting faster, or the same time feeling easier, is progress regardless of where the number sits against anyone else.

5K Pace Calculator

Pick a 5K target and this works out the pace you need to hold, split by kilometre and by 400 metre lap, along with a race plan for how to spread the effort. It is built around the target rather than around the arithmetic: choose sub-25, sub-20 or type your own, and everything else follows from it. A...

YOUR 5K TARGET

TARGET TIME — mm:ss

COMMON TARGETS

YOU NEED TO HOLD

5:00 / km

PER MILE

8:03

PER LAP

2:00

SPEED

12.00 km/h

That is 2:00 for every one of the twelve full laps, then 1:00 for the closing 200 metres — 7.46 mph throughout.

TRACK SPLITS — 400 m LAPS

Lap 1

400 m