Pace Calculator
Calculate pace, finish time, or distance for any run. Results update instantly.
per mile
per mile
Split Times
Even splits at your current pace
| Distance | Split Time | Elapsed |
|---|
Race Time Predictions
Enter a known race result to predict other distances using the Riegel formula
| Race | Predicted Time | Predicted Pace |
|---|
Formula: T2 = T1 × (D2 ÷ D1)1.06 — Peter Riegel, 1977
How to Use the Running Pace Calculator
This pace calculator handles the three core running math problems in one place, all updating live as you type. Switch between miles and kilometers at any time — all values convert automatically.
Mode 1: Calculate Your Pace
Enter a distance (choose from 1 mile, 5K, 10K, half marathon, marathon, or a custom value) and a finish time. The calculator returns your pace in minutes:seconds per mile or per kilometer, your equivalent speed in mph or kph, and the same pace expressed in the other unit system. Use this to analyze training runs or set realistic race targets.
Mode 2: Calculate Finish Time
Select a race distance and enter your target pace in minutes and seconds per mile (or per km). The calculator shows your projected finish time. This is useful when planning a race strategy — for example, if you want to finish a half marathon in under two hours, you need to run faster than 9:09 per mile (5:41/km).
Mode 3: Calculate Distance
Enter how long you plan to run and at what pace. The calculator tells you how far you will cover. Perfect for time-based training plans where you run for a fixed duration rather than a fixed distance.
Reading the Splits Table
The splits table shows your cumulative time at each interval assuming a perfectly even effort. For miles, splits appear at every mile marker. For kilometers, splits appear every kilometer. The last row shows your total time for the full distance. Consistent splits are the hallmark of a well-paced run — most recreational runners start too fast and positive-split their races.
Race Time Predictions with the Riegel Formula
The Riegel formula (T2 = T1 × (D2 ÷ D1)1.06) was published by Peter Riegel in 1977 and remains one of the most widely used tools for predicting race performance at unfamiliar distances. The exponent 1.06 captures the physiological reality that longer races require proportionally more energy than shorter ones — you cannot simply double a 5K pace to estimate a 10K time. Enter any known race result (from a recent 5K to a half marathon) and the table will show projected times for eight standard race distances. Predictions are most accurate when the input distance is within 2–3x of the target distance.
Common Running Pace Reference
A 6:00/mile (3:44/km) pace is elite-amateur territory, producing a sub-26:00 5K or sub-4:11 marathon. A 10:00/mile (6:12/km) pace is a solid recreational goal. Absolute beginners often start around 13:00–15:00 per mile (8:04–9:19/km). For most training runs, use a "conversational pace" — easy enough to speak in full sentences — which falls roughly 90–120 seconds per mile slower than your 5K race pace.