5K Pace Calculator with 400 m & 1 km Splits

The 5K Pace Calculator works backward from a goal finish time to the pace that gets you there. The distance is locked at the standard 5,000 m (3.107 mi), so there is only one number to type: enter your target, pick miles or kilometers, and read off the required pace, speed, 400 m lap time, and even-pace 1 km split. From there you can build full training paces around the target or compare goal times across distances.

Goal time
Pace unit Display pace and speed in miles or kilometres.
Required pace per mile8:03 /mi
Pace per kilometre5:00 /km
Required speed7.46 mph
Per 400 m lap2:00
1 km split (even pace)5:00

25:00 · mi

How it works

required pace = goal time ÷ 3.10686 mi (or ÷ 5 km)

Divide the goal time by the distance and you have the required pace; because a 5K is always 5,000 m, the goal time is the only input that can move the answer. The math runs in meters and seconds, then presents pace per mile, pace per kilometer, and speed together, so the two unit views never disagree. Two extra outputs make the number usable on a track: a 5K works out to 12.5 laps of a standard 400 m oval, so you get a per-lap target, and the even-pace 1 km split shows what each kilometer marker should read on race day.

Sources

FAQ

What pace do I need to break 25 minutes in a 5K?

Enter 25:00 as the goal and the tool returns 8:03 per mile, which is exactly 5:00 per kilometer. Hold anything quicker than that across the full distance and you come home under 25 minutes.

What does a sub-20 5K demand?

A 19:59 goal works out to 6:26 per mile or 4:00 per kilometer — every kilometer under four minutes and every 400 m lap around 1:36. It is a serious amateur benchmark, so confirm the pace feels sustainable in workouts before racing it.

What pace gets me under 30 minutes?

A 30-minute 5K averages 9:39 per mile, or a clean 6:00 per kilometer. Many runners chase this goal in their first year after finishing a beginner program, and the even 1 km split makes it easy to check progress at each course marker.

Why do the mile and kilometer paces look so different?

They describe the same speed over different distances — a mile is 1.609344 km, so the per-mile figure always reads larger. The calculator shows both at once, which helps when the course marks kilometers but your watch is set to miles.

Why might my actual splits differ from the calculator?

The splits assume you run every meter at the same speed. Real 5Ks rarely cooperate — a crowded start, a hill, wind, or heat can cost several seconds per kilometer. Treat the even-pace numbers as the average you need, not a rule for each individual kilometer.

What is a realistic first 5K goal?

Most new runners who complete a beginner plan finish between 30 and 35 minutes, which is 9:39–11:16 per mile (6:00–7:00 per km). Punch a time from that range into the calculator, then move the goal toward sub-30 and sub-25 as fitness builds.

How do faster runners use a required-pace number?

As a ceiling for workouts and a check against drift on race day. The per-400 m figure converts the goal straight into interval targets on the track, and starting the first kilometer 5–10 seconds easier than the even split leaves something for a fast final lap.

The pace, lap, and split figures are straight arithmetic on the goal you type in — they tell you what the target requires, not whether current fitness can deliver it. Use them for pacing plans, not as coaching or medical guidance.

Embed this calculator

Add the 5k pace calculator with 400 m & 1 km splits to your website or club page — free, no sign-up. Paste this snippet where you want the calculator to appear:

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