Pace Calculator (Distance, Time & Pace Converter)
Free running pace calculator that converts between distance, time, and pace. Enter distance and time to get your pace, distance and pace to get your time, or time and pace to get your distance. Includes a finish time reference table for 5K, 10K, half marathon, and marathon.
Common Race Distances
| Race | Distance (km) | Distance (mi) |
|---|---|---|
| 5K | 5.00 km | 3.11 mi |
| 10K | 10.00 km | 6.21 mi |
| Half Marathon | 21.10 km | 13.11 mi |
| Marathon | 42.20 km | 26.22 mi |
Pace Chart (Estimated Finish Times for Common Races)
| Pace (/km) | Pace (/mi) | 5K | 10K | Half Marathon | Marathon |
|---|---|---|---|---|---|
| 3:00 /km | 4:50 /mi | 15:00 | 30:00 | 1:03:18 | 2:06:35 |
| 3:30 /km | 5:38 /mi | 17:30 | 35:00 | 1:13:50 | 2:27:41 |
| 4:00 /km | 6:26 /mi | 20:00 | 40:00 | 1:24:23 | 2:48:47 |
| 4:30 /km | 7:15 /mi | 22:30 | 45:00 | 1:34:56 | 3:09:53 |
| 5:00 /km | 8:03 /mi | 25:00 | 50:00 | 1:45:29 | 3:30:59 |
| 5:30 /km | 8:51 /mi | 27:30 | 55:00 | 1:56:02 | 3:52:04 |
| 6:00 /km | 9:39 /mi | 30:00 | 1:00:00 | 2:06:35 | 4:13:10 |
| 6:30 /km | 10:28 /mi | 32:30 | 1:05:00 | 2:17:08 | 4:34:16 |
| 7:00 /km | 11:16 /mi | 35:00 | 1:10:00 | 2:27:41 | 4:55:22 |
| 7:30 /km | 12:04 /mi | 37:30 | 1:15:00 | 2:38:14 | 5:16:28 |
| 8:00 /km | 12:52 /mi | 40:00 | 1:20:00 | 2:48:47 | 5:37:34 |
Estimated finish times assuming a constant pace per km throughout the race. In practice, most runners target a slightly conservative early pace to leave room for a negative split rather than fading late (a positive split).
What Is a Pace Calculator?
A pace calculator converts between distance, time, and pace (the time it takes to cover one kilometer or mile) — given any two of the three values, it solves for the third. This makes it easy to answer questions like "how long will it take me at this pace?" or "what pace do I need to hit my target finish time?", which are central to race planning and training.
This tool supports distance presets for 5K, 10K, half marathon, and marathon, and lets you switch between km and mile units. All calculations run entirely in your browser — nothing you enter is sent to a server.
How to Use the Pace Calculator
- Choose what to calculate Pick one of "Calculate Pace", "Calculate Time", or "Calculate Distance" depending on which value you want to find.
- Choose the distance unit Select km or mi. The pace unit follows whichever distance unit you choose.
- Enter the other two values Fill in the two values other than the one you selected. Choosing a distance preset fills the distance field automatically.
- Check the result The missing value, along with your speed (km/h or mi/h), is calculated automatically from the two values you entered.
Tips for getting more out of it
- For race day, plan an even pace based on your target time, then aim for a slightly conservative first half so you can finish strong with a negative split rather than fading late.
- When setting a marathon goal pace, build in a few minutes of buffer beyond your target time to account for water stops and bathroom breaks.
- In training, mix paces to match your goal: slower long runs (LSD) build endurance, while pace runs and interval sessions faster than race pace build speed.
- Switch between km and mi to match the race you are training for — many US and UK races post distance markers in miles, while most international races use kilometers.
- Logging pace alongside heart rate or perceived effort makes it easier to notice how your condition varies day to day even at the same pace.
Ways to Use the Pace Calculator
Set your race pace from a goal time
Enter a goal time like "sub-4:00" for a marathon to find the per-km pace you need to maintain to hit it.
Check your current training pace
Enter the distance and time of your usual run to see your current pace and use it as a benchmark for future training.
Plan pace runs and interval workouts
From a target pace and distance, calculate the split time for each lap or repeat in your workout.
Estimate walking or hiking time
Beyond running, use distance and pace to estimate how long a walk or hike will take.
Running Pace Glossary
- Pace
- The time it takes to run one kilometer or mile. A pace of "5:00/km" means running one kilometer in 5 minutes.
- Speed
- The distance covered in one hour (in km/h or mi/h). Speed and pace describe the same effort in different units — a faster pace means a higher speed.
- Even split
- A pacing strategy of running at a nearly constant pace throughout the race, which helps avoid fading in the final stretch.
- Negative split
- Running the second half of a race faster than the first half. Holding back early leaves reserve energy for a stronger finish and more consistent overall time.
- Positive split
- When the second half of a race is slower than the first half, often caused by starting too fast.
Frequently Asked Questions
Side Note — Why Is a Marathon Exactly 26.2 Miles (42.195 km)?
The marathon's oddly specific distance of 42.195 km has a widely told origin story. At the 1908 London Olympics, the course was set to start at Windsor Castle and finish inside the Olympic stadium in London — reportedly positioned so the finish line sat in front of the Royal Box for the benefit of the watching royal family — and this routing happened to produce the now-famous distance.
Before that race, marathon distances varied by host city, typically landing somewhere around 40 km. The 42.195 km distance became the official standard only in 1921, when the International Amateur Athletic Federation (now World Athletics) formally adopted the 1908 London course length as the fixed standard for all future marathons.
Today, 5K, 10K, the half marathon (21.0975 km, exactly half a marathon), and the full marathon form a globally standardized set of race distances used at events worldwide. Pace calculators typically reference these same four distances when estimating finish times.