Your running pace is your finish time divided by your distance. A 25-minute 5K is 5:00 per kilometer, or about 8:02 per mile. The math is not the hard part. The hard part is accepting what the number tells you about your current fitness rather than your hopes.
Most runners make pacing complicated because they want it to be a personality test. It is not. Pace is a ratio. Once you treat it that way, you can plan workouts, read a race result, and stop pretending that your easy run was somehow secretly fast.
The two units
Running pace is usually expressed as minutes per kilometer or minutes per mile. The relationship is fixed: one mile is 1.609344 kilometers.
To convert from minutes per kilometer to minutes per mile, multiply by 1.609344. A 5:00/km pace becomes 8:03/mile. To go the other way, divide by 1.609344. An 8:00/mile pace is 4:58/km.
Pick one unit and stay with it for training. Mixing units is how you end up running 4:30 kilometers because you confused kilometers with miles and then blame the watch.
Average pace, splits, and what they hide
Average pace is the total time divided by the total distance. It is useful, but it hides the story. A 5K run at an average of 5:00/km could mean every kilometer was exactly 5:00, or it could mean the first two were 4:30 and the last three were 5:20. Those are different runs.
Splits are the per-kilometer (or per-mile) breakdown. Even splits mean each segment is the same time. They are the mark of a controlled effort. Positive splits mean you started too fast and paid for it. Negative splits mean you finished faster than you started, which is harder to execute but easier on the body.
For the solo runner, even splits are especially valuable because there is nobody else’s pace to chase. You are not surging because the group surged. You are simply holding the number you decided to hold. Discipline, not drama.
Predicting one race from another
If you run a recent 5K in 25:00, you can estimate what you might run for 10K or a half marathon using the Riegel formula:
T2 = T1 × (D2 / D1)^1.06
The exponent 1.06 accounts for the fact that endurance does not scale perfectly with distance. A runner who can hold a certain effort for 5 kilometers cannot hold exactly half that effort for 10 kilometers. The formula captures the slowdown.
It assumes you are trained for the target distance. If your longest run in the last month was 6 kilometers, the formula will optimistically predict a half marathon time your legs do not actually own. The math describes physiology, not magic.
This is where the solo runner has an advantage: there is no social pressure to sign up for a longer race before the training is there. Use the prediction as a checkpoint, not a contract.
Race pace versus training pace
Race pace is the pace you can hold for the full distance on race day. Training paces are different. Easy runs are slower. Tempo runs are around threshold. Intervals are faster, with recovery between reps.
The common mistake is to run every training run at something close to race pace. That pace feels productive, but it accumulates fatigue without delivering the specific stimulus of either true easy running or true speed work. Easy is easy. Hard is hard. The middle is a grey zone that makes you tired without making you faster.
If you want race-pace context, plug a recent finish time into the Solo Pace Calculator. It returns your average pace, kilometer splits, mile pace, and the Riegel-based predictions for standard distances. The tool does not require an account, a GPS track, or an explanation to anyone.
When the number lies
Pace is only as good as the inputs. A GPS watch can drift by several percent in tree cover or between tall buildings. A treadmill can be miscalibrated by the gym staff who last touched it in 2019. A race course can be measured accurately, but your watch might disagree because you did not run the tangents.
Use pace as feedback, not as a verdict. A single bad split does not mean you are unfit; it might mean you stopped for a light, ran into a headwind, or misread a turn. Look at patterns over weeks, not seconds.
The same applies to race predictions. They get better as your race results get more honest. A time trial run alone on a flat Tuesday morning is usually a better input than a race where you got caught behind a crowd for the first kilometer and then sprinted the last.
Pace without a watch
You do not need a GPS device to calculate pace. You need a known distance and a timer. A standard track gives you 400 meters. A measured loop from your door gives you a fixed route. A treadmill display gives you distance even if the calibration is questionable.
Run the known distance, note the time, and divide. If you ran 2 kilometers in 12 minutes, your pace is 6:00/km. A phone stopwatch and a remembered route are enough for the first several months of training. The watch can come later, once the habit is established and the numbers actually mean something.
Frequently asked, quietly
Why does my mile pace look so much slower than my kilometer pace? It is the same effort expressed in a longer unit. A mile is roughly 1.6 kilometers, so each mile contains more time than each kilometer at the same speed. The pace itself is not worse; the unit is bigger.
Is average pace the same as current pace on my watch? No. Current pace is an estimate of how fast you are moving right now, based on a few seconds of data. Average pace is the total time divided by the total distance. Train and race by average pace; current pace is too noisy.
Can I use pace for interval workouts? Yes, but perceived effort matters more for short reps. A 400-meter repeat is over too quickly for pace feedback to be useful in the moment. Save pace targets for repeats of 800 meters or longer, or for tempo runs where the duration is the point.
Do I need to run exactly even splits to have a good run? No. Even splits are a skill, not a moral requirement. Beginners should aim for “mostly controlled” rather than perfectly even. The goal is to avoid the catastrophic positive split, not to split the atom.
What if my pace is slower than I want it to be? Then your current fitness is slower than you want it to be. Pace is an output, not an identity. You change it by training consistently at the right intensities, not by willing your next run to be faster.
Pace is a ratio. That is the entire trick. Use the calculator below to turn your recent time into a number you can actually train with, then go run it alone.