What is Pace Calculator?

Enter any two of pace, distance, and time to get the third. You also get split times, race predictions up to 50K, and an estimated VO₂max fitness snapshot.

Switch units between kilometers and miles at any time, and split times appear automatically for each kilometer or mile of the entered distance. Race predictions assume an even effort, which is realistic for short distances but increasingly optimistic past the half-marathon mark as fatigue compounds. Use the predictions to set a target pace, then verify with a long training run before race day.

How to use

1. Choose what you want to calculate: pace, time, or distance.
2. Enter the two known values (e.g., distance and time to find your pace).
3. See your result plus race predictions for 5K, 10K, half marathon, marathon, and 50K, with per-km or per-mile splits and a VO₂max fitness snapshot.

When to use

• Setting a goal pace for an upcoming 5K, 10K, or marathon.
• Working out how long a training run will take before you leave.
• Comparing a track session in minutes per mile to a treadmill display in km/h.

Result

You ran 5 kilometers in 25 minutes. Your pace is 5:00 per km (8:03 per mile). At this pace, a 10K would take 50:00 and a half marathon about 1:45:15.

FAQ

Are the race predictions realistic?

They assume you can hold the same pace at any distance, which is true within about 20%. A 5K time predicts a marathon roughly 4.6 times longer. In practice most runners drop 10 to 30 seconds per kilometer between a 10K and a marathon, so use the prediction as a ceiling.

Should I train at my goal race pace?

Only some of the time. A common ratio is 80% easy running below goal pace and 20% at or above it. Easy runs build the aerobic base; pace work teaches your body the goal effort. Pure race-pace training all the time leads to plateaus and injuries.

What is a good marathon pace for a beginner?

For a first marathon, finishing matters more than time. Most first-timers run 6:00 to 7:30 per kilometer (9:40 to 12:00 per mile), which projects a 4h13 to 5h16 finish. Plug those paces into the calculator to see split times for fueling stops.

How do I convert between pace and speed?

Pace is the inverse of speed. A 5:00/km pace equals 12 km/h (60 minutes divided by 5). A 7:00/mile pace equals about 8.57 mph (60 divided by 7). The calculator handles this implicitly when you switch units, so you don't have to do the math.

Why are the split times the same number for every kilometer?

The calculator assumes you hold an even split, which is the most efficient pacing strategy. Real-world splits vary with hills, weather, and fatigue. A positive split (slowing down) is common; a negative split (speeding up) is the hallmark of a well-paced race. Open the Conditions panel to add heat or altitude and see how much they push the prediction back.

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