What’s the difference between pace and speed?

They’re the same information viewed two ways: pace is time per distance (minutes per kilometer) and speed is distance per time (km/h). A lower pace means a faster run, while a higher speed does. Runners usually talk in pace because it maps directly onto split times; cyclists and drivers usually talk in speed.

How do I convert min/km to min/mile?

Multiply the pace in seconds per kilometer by 1.609344, because one mile is 1.609344 km. For example, 5:00 min/km is 300 seconds per km, and 300 × 1.609344 ≈ 483 seconds per mile — about 8:03 min/mile. This tool reports pace per kilometer.

What is a negative split?

Running the second half of a race faster than the first half — a pacing strategy many distance runners aim for, since starting too fast often costs more time late in the race than it saves early. This calculator shows your overall average; to compare halves, enter each half’s distance and time separately and compare the two paces.

How do I use pace for race planning?

Multiply your target pace by the race distance: 10 km at 5:00 min/km takes exactly 50:00, and a half marathon (21.0975 km) at the same pace takes about 1:45:29. Working backward also works — enter the race distance and your goal time, and the pace shown is what you need to hold. A marathon is 42.195 km.

Why does my GPS watch show a slightly different pace?

GPS positions wander a little, which usually adds distance and makes the watch read a faster pace than the certified course length implies. Watches may also use moving time rather than elapsed time, pausing when you stop. This calculator does the exact division on the numbers you enter, so it matches official results when you use the official distance and your chip time.

No. The pace and speed are calculated entirely in your browser, and nothing you enter leaves your device.

Running Pace Calculator

Calculate your pace per km and speed from distance and time.

Runs in your browser — files never leave your device

DistancekmMinutesSeconds

Pace

5:00 /km

Speed

12 km/h

How it works

This calculator converts a distance and a finishing time into the two numbers runners actually train with: pace (how long each kilometer takes) and average speed (how far you cover per hour). Pace and speed are reciprocals of each other — pace = time ÷ distance and speed = distance ÷ time — and a lower pace means a faster run.

The tool first converts your time to seconds (minutes × 60 + seconds), then computes seconds per kilometer = total seconds ÷ distance in km. It displays that as minutes:seconds per kilometer, rounding the seconds part to the nearest whole second. Average speed = distance ÷ time in hours, rounded to one decimal place in km/h.

Worked example: 10 km in 50 minutes 0 seconds. Total time = 50 × 60 = 3,000 seconds, so 3,000 ÷ 10 = 300 seconds per kilometer, displayed as 5:00 min/km. Speed = 10 ÷ (3,000 ÷ 3,600) = 12 km/h. If you think in miles, multiplying 300 s/km by 1.609344 gives about 483 seconds per mile — roughly 8:03 min/mile.

Because the calculation divides total time by total distance, the result is your average pace — it says nothing about how evenly you ran, and two runners can both average 5:00 min/km with one holding steady splits and the other fading badly. For race planning, invert the math: at a target pace of 5:00 min/km, 10 km takes exactly 50:00. Keep in mind that GPS-measured distance carries some error, so a watch’s pace can differ slightly from this calculation on a certified course. Training numbers like these are general guidance only, not medical advice — build distance and speed gradually and check with a professional if you have health concerns.

Frequently asked questions

What’s the difference between pace and speed?: They’re the same information viewed two ways: pace is time per distance (minutes per kilometer) and speed is distance per time (km/h). A lower pace means a faster run, while a higher speed does. Runners usually talk in pace because it maps directly onto split times; cyclists and drivers usually talk in speed.
How do I convert min/km to min/mile?: Multiply the pace in seconds per kilometer by 1.609344, because one mile is 1.609344 km. For example, 5:00 min/km is 300 seconds per km, and 300 × 1.609344 ≈ 483 seconds per mile — about 8:03 min/mile. This tool reports pace per kilometer.
What is a negative split?: Running the second half of a race faster than the first half — a pacing strategy many distance runners aim for, since starting too fast often costs more time late in the race than it saves early. This calculator shows your overall average; to compare halves, enter each half’s distance and time separately and compare the two paces.
How do I use pace for race planning?: Multiply your target pace by the race distance: 10 km at 5:00 min/km takes exactly 50:00, and a half marathon (21.0975 km) at the same pace takes about 1:45:29. Working backward also works — enter the race distance and your goal time, and the pace shown is what you need to hold. A marathon is 42.195 km.
Why does my GPS watch show a slightly different pace?: GPS positions wander a little, which usually adds distance and makes the watch read a faster pace than the certified course length implies. Watches may also use moving time rather than elapsed time, pausing when you stop. This calculator does the exact division on the numbers you enter, so it matches official results when you use the official distance and your chip time.
Is my data uploaded?: No. The pace and speed are calculated entirely in your browser, and nothing you enter leaves your device.

Running Pace Calculator

How it works

Frequently asked questions

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