Compute running speed metrics. Select the variable you want to solve, input the other parameters, and view a complete split time breakdown.
| Distance | Metric (per km) | Imperial (per mi) |
|---|---|---|
| 1 km | 5:00 | 8:03 |
| 1 mile | 8:03 | 12:57 |
| 5 km | 25:00 | 40:15 |
| 10 km | 50:00 | 1:20:30 |
| Half Marathon (21.097 km) | 1:45:29 | 2:49:53 |
| Marathon (42.195 km) | 3:30:58 | 5:39:46 |
A track coach structuring interval sessions for their middle-distance runners reviews their target pace splits. In distance running, pace represents the primary training metric, establishing speed control and energy expenditure over specific race distances.
Pace is a measure of speed, defined as the time taken to cover a specific unit of distance. Unlike cycling or driving (measured in speed, e.g. km/h or mph), running speed is expressed as pace (e.g. minutes per kilometer or minutes per mile).
Running velocity is the product of stride length and stride frequency (cadence). Aerobic speed is limited by cardiorespiratory capacity (VO2 max) and running economy (the energy required to maintain a given pace). Maintaining a specific pace requires a balance of oxygen delivery to muscles and glycogen energy conversion.
Even Splits: Maintaining a completely stable pace throughout the race. This represents the most energetically efficient pacing strategy for distances over 5K, as it avoids early lactic accumulation.
Negative Splits: Running the second half of a race faster than the first half. Highly recommended for marathon runners to avoid hitting the wall early.
Positive Splits: Starting fast and slowing down in the second half. Usually the result of poor pacing or early fatigue, causing massive oxygen debt and glycogen depletion.
Your body stores approximately 400 to 500 grams of glycogen in muscles and the liver. During intense running, glycogen is the primary fuel. Running above your lactate threshold drains these glycogen stores rapidly. Using a pace calculator allows runners to identify their aerobic zone pace, preserving glycogen and extending endurance during long races.
Distance metrics convert miles to kilometers (1 mile = 1.609344 km) or kilometers to miles before calculations, ensuring accuracy. Calculated times are formatted into hours, minutes, and seconds. Splits are generated directly from the solved pace.
Multiply the decimal pace per kilometer by 1.609344. For example, a 5:00/km pace is `5.00 × 1.609344 = 8.046`, which is equivalent to approximately 8 minutes and 3 seconds per mile.
For beginner runners, a comfortable, conversational pace is between 6:30 and 8:00 minutes per kilometer (10:30 to 13:00 minutes per mile). The focus should be on building duration rather than speed.
Generally, treadmill running is slightly easier due to the lack of wind resistance and the assist of the moving belt. Setting the treadmill incline to 1.0% simulates outdoor running aerodynamic costs.
Race Time Predictor — Estimates future race times based on recent results.
Heart Rate Zones — Establishes heart rate training targets.
VO2 Max Calculator — Computes peak aerobic performance indices.