Running Pace Calculator

How to use the pace calculator

Enter any two of the three values — distance, time and pace — and the third is calculated instantly. Know your distance and finish time, get your pace. Know your target pace and distance, get the finish time. Results appear in both km and miles, plus your average speed in km/h and mph.

What your pace tells you

Pace is time per kilometre or mile — the number your GPS watch shows at each lap. It is more useful than speed for most runners because it matches how a race unfolds: every kilometre ticks by, and the split time tells you immediately whether you are ahead or behind your plan.

A pace of 5:30 /km means you cover one kilometre every five minutes and thirty seconds. Converting to speed: 60 ÷ 5.5 = 10.9 km/h. This tool does all of that for you.

From pace to race plan

Once you know your current pace, the other calculations fall into place:

• Splits: Take your goal pace and enter it into the splits calculator to see the exact per-kilometre or per-mile times for any target finish time.
• Training zones: Enter your threshold pace into the training pace zones calculator and get the five paces — from easy to repetition — that structure your training week.
• Race predictions: Enter a recent timed result into the race time predictor to see what you should be capable of over other distances.

Common pace benchmarks

A few round-number reference points to build your intuition:

• 5 km in 30:00 → 6:00 /km (10.0 km/h)
• 5 km in 25:00 → 5:00 /km (12.0 km/h)
• 10 km in 50:00 → 5:00 /km (12.0 km/h)
• Half marathon in 2:00:00 → 5:41 /km (10.5 km/h)
• Marathon in 3:30:00 → 4:59 /km (12.1 km/h)
• Marathon in 4:00:00 → 5:41 /km (10.5 km/h)

Why accurate pace matters more than you think

Many runners start races by feel and end up paying for it in the final kilometres. Knowing your exact pace — and checking it regularly against your watch — removes the guesswork from pacing. A single kilometre run at 15 seconds per km too fast feels manageable early on; spread over 42 km, it costs minutes. The pace calculator gives you the number to programme into your watch and hold on race day.

For the full story on how to calculate and apply pace to training and racing, read the running pace guide.

How the math works

Underneath the calculator sits one relationship: pace × distance = time. Whichever two values you enter, the calculator rearranges that formula to solve for the third:

• Distance and time known → pace = time ÷ distance. Divide your total seconds by the distance in kilometres (or miles) to get seconds per unit.
• Distance and pace known → time = pace × distance. Multiply your per-km (or per-mile) pace by the number of units to get the total time.
• Pace and time known → distance = time ÷ pace. Divide total time by pace to see how far that pace and duration would carry you.

Speed is the same relationship viewed the other way round: speed = distance ÷ time, expressed in distance per hour rather than time per distance. Convert your total seconds to hours (divide by 3,600), then divide distance by that figure to get km/h or mph.

The only extra step is switching between kilometres and miles, and that's a single fixed multiplier: 1 mile = 1.60934 km. Because a mile is the longer unit, covering it takes proportionally longer than covering a kilometre at the same effort — so:

• Pace per mile = pace per km × 1.60934. Every second you spend per kilometre becomes 1.60934 seconds per mile, since a mile packs in 1.60934 kilometres' worth of running.
• Speed in mph = speed in km/h ÷ 1.60934. The same logic in reverse — mph counts fewer, longer units per hour, so you divide instead of multiply.

That's the entire calculator: one division or multiplication to move between pace, time and distance, and one fixed ratio to move between metric and imperial units.

Worked example: 10K in a goal time of 50:00

Say your goal is to run a 10K in 50:00 and you want the exact numbers to train and race with.

• Step 1 — convert the goal time to seconds. 50 minutes = 50 × 60 = 3,000 seconds.
• Step 2 — divide by the distance to get pace per km. 3,000 ÷ 10 = 300 seconds per km, which is 5:00 /km.
• Step 3 — convert to pace per mile. 300 × 1.60934 = 482.8 seconds, which rounds to 8:03 /mile.
• Step 4 — compute speed. 3,000 seconds is 3,000 ÷ 3,600 = 0.8333 hours, so 10 ÷ 0.8333 = 12.0 km/h. In miles per hour: 12.0 ÷ 1.60934 = 7.46 mph, which you'd typically read off a console as 7.5 mph.
• Step 5 — what to programme into your watch. If your watch is set to metric, the number to hold is 5:00 /km (or a 12.0 km/h current-speed display on a treadmill-style screen). Set to imperial, hold 8:03 /mile (7.5 mph). Either setting describes exactly the same effort — the calculator just gives you both so you can match whatever your device shows.

Plug 10 km and 50:00 into the calculator above and you'll see precisely these figures. Change the goal time and every number updates instantly, so you can test how a faster or slower target shifts your per-km and per-mile splits before you commit to a race plan.