Enter a distance and time to get your pace per mile and per kilometer, your speed, and predicted finish times for common race distances.
Pace is the time it takes to cover one mile or one kilometer, and it's the number runners use to plan training and races. Enter how far you ran and how long it took, and this calculator returns your pace, your speed, and projected times for standard race distances.
Pace and speed describe the same thing from opposite directions. Pace is time per distance (for example 8:00 per mile), while speed is distance per time (7.5 mph). Runners usually think in pace because it maps directly to splits, while treadmills and cyclists use speed. The calculator shows both.
The predicted finish times use Riegel's formula, which scales a known time to other distances using an endurance exponent. It's a solid estimate for races from 5K to the marathon, assuming you train appropriately for the longer distance. Real marathon results also depend on fueling, terrain, and heat.
Most plans prescribe different paces for different runs: easy runs well slower than race pace, tempo runs near threshold, and intervals faster than race pace. Knowing your current pace from a recent effort lets you set those training paces correctly and track improvement over time.
Tip: For the most accurate race predictions, base your input on a recent hard effort at 5K or longer. Short sprints over-predict your endurance pace because you can't hold that speed for a marathon.