About the pace calculation
Pace is time per unit distance, and it is the number runners actually train and race by. This converts between pace, speed, and finish times, so you can check whether a training run is on target for a goal race.
Formula
Pace (s/km) = total seconds ÷ distance in km
Speed (km/h) = distance in km ÷ (total seconds ÷ 3600)
1 mile = 1.609344 kmWorked example
10 km in 50 minutes (3,000 s): pace = 3000 ÷ 10 = 300 s/km, which is 5:00 min/km. Speed = 10 ÷ (3000÷3600) = 12.0 km/h.
Frequently asked questions
Are the projected race times realistic?
They assume you can hold the same pace at every distance, which nobody can. A common correction is Riegel's formula, where predicted time scales with distance to the power 1.06. Expect a real marathon to be slower than the straight extrapolation shown here.
What is a good 5K pace?
It depends entirely on training age. Recreational runners commonly finish between 25 and 35 minutes, which is roughly 5:00-7:00 min/km. Competitive club runners go under 20 minutes, and elites under 14.
Should I train at race pace?
Mostly no. The widely used 80/20 rule puts around 80% of training volume at an easy, conversational pace and only 20% at hard efforts. Training everything at race pace is the fastest route to a plateau or an injury.
Sources
- Riegel PS — Athletic records and human endurance (1981)