Pace, time and distance formulas
Pace = Time ÷ Distance
Time = Pace × Distance
Distance = Time ÷ Pace
Time = Pace × Distance
Distance = Time ÷ Pace
1 mile = 1.609344 km. To convert a pace per kilometer to a pace per mile, multiply by 1.609344; to go the other way, divide.
Example: You run a 10K in 50:00. Your pace is 50 ÷ 10 = 5:00 per km, or 5:00 × 1.609 = 8:03 per mile, a speed of 12 km/h (7.5 mph). Using Riegel’s formula, a 25:00 5K predicts about 52:07 for 10K, 1:55:00 for a half marathon and 3:59:47 for a marathon.
Common race pace targets
| Goal | Pace per km | Pace per mile |
|---|---|---|
| 5K in 30:00 | 6:00 | 9:39 |
| 10K in 60:00 | 6:00 | 9:39 |
| Half marathon in 2:00:00 | 5:41 | 9:09 |
| Marathon in 4:00:00 | 5:41 | 9:09 |
| Marathon in 3:30:00 | 4:59 | 8:01 |
Planning training time? The time duration calculator adds up sessions for you.
Frequently asked questions
How do I calculate running pace?
Divide your total time by the distance. A 10 km run in 50 minutes is 50 ÷ 10 = 5 minutes per kilometer. To convert to minutes per mile, multiply the per-kilometer pace by 1.609: 5:00/km ≈ 8:03/mile.
What pace do I need for a sub-4-hour marathon?
A 4-hour marathon requires an average of 9:09 per mile or 5:41 per kilometer. Most runners aim a few seconds faster to allow for water stations and crowding.
How accurate are the race time predictions?
Predictions use Peter Riegel’s formula, T₂ = T₁ × (D₂ ÷ D₁)1.06. They work best for distances within a factor of about four of your known race and assume equal training for the longer distance. Marathon predictions from a 5K are often optimistic for less-experienced runners.
What is a good running pace for a beginner?
Many beginners run between 10 and 13 minutes per mile (6:15–8:05 per km). An easy pace — one at which you can hold a conversation — is the right pace for most training runs.