TOOL · TRAINING
Pace, Effort & Race Time Calculator
Plug in any run. Get your pace per mile and per kilometer, a realistic look at your race times, and a simple way to tell if your easy days are actually easy.
Reviewed October 20, 2026 · By Nick Merich, GRYT Run Club
1 · Distance
2 · Your time
Pace per mile
9:39
Pace per km
6:00
Speed
6.2 mph
3 · Predicted race times
| Race | Finish | Pace / mi |
|---|---|---|
| 5K | 30:00 | 9:39 |
| 10K | 1:02:33 | 10:04 |
| 10 mile | 1:43:35 | 10:21 |
| Half | 2:18:00 | 10:32 |
| Marathon | 4:47:44 | 10:58 |
Predictions use Riegel's formula and assume you have trained for the longer distance. Expect hilly courses like the EQT Pittsburgh 10 Miler to run a little slower.
Easy is an effort, not a number
The most common mistake we see on Saturdays is not running too slow. It is running every run too fast. Pace changes with hills, heat, sleep, and stress. Effort does not lie, which is why the talk test works better than a watch for most runs.
Easy
Up to 6 of 10
You can talk in full sentences. Singing would be a stretch.
Most of your week, and every GRYT Saturday.
Steady
Effort 6 to 7 of 10
Short sentences only. You'd rather listen than talk.
Tempo efforts, the last mile of a long run.
Hard
Effort 7 to 9 of 10
A few words at a time before you need a breath.
Hill repeats, race day, once a week at most.
The CDC uses the same idea: during moderate activity you can talk, but not sing, and during vigorous activity you cannot say more than a few words without pausing for a breath. On their 0 to 10 scale, moderate effort is a 5 or 6 and vigorous starts at 7 or 8.
How to use your numbers
Pick a goal race, then work backward
Run a recent 5K or a hard 2 miles, enter it above, and look at the prediction for your goal distance. If the gap between today and your goal is big, give yourself more weeks, not faster workouts. Our Pittsburgh race calendar shows how many weeks you have left for each local race.
Recheck every four to six weeks
Fitness shows up slowly. Retest on the same route in similar weather so you are comparing like with like. The mostly flat, crushed-limestone stretch of the Montour Trail out of Peterswood Park is a good test strip.
Do not chase a number on hills
South Hills running means climbing. Let pace drop on the uphills, hold the same effort, and let gravity give it back on the way down.
Frequently asked questions
What pace is a GRYT Saturday run?
Whatever pace you can hold a conversation at. GRYT is no-drop, so walkers, joggers, and marathoners share the same out-and-back on the Montour / Peters Trail and regroup at the end. There is no pace requirement.
How accurate are race time predictions?
They are a starting point. Riegel's formula assumes you have trained for the longer distance and that the courses are similar. Predictions from a 5K to a marathon are the least reliable, and hilly Pittsburgh courses usually run slower than flat ones.
What is easy pace?
Easy pace is effort, not a number. If you can talk in full sentences but could not sing, you are in the moderate zone the CDC describes. Most of your weekly running should feel like that.
Sources we checked
- CDC: How to Measure Physical Activity Intensity · talk test and 0 to 10 effort scale
- Peter Riegel, race time prediction formula · T2 = T1 × (D2 / D1)^1.06
- CDC: Getting Started With Physical Activity · 150 minutes of moderate activity a week
General guidance, not medical advice. If you have a heart, lung, or other health condition, check with your doctor before changing how you train.