Skip to content
ForgePlug — Logo
health100% Browser-Based

Running Pace Calculator

A premium Running Pace Calculator for runners of every level. Enter a distance and time to instantly get your pace per km and per mile, speed in km/h and mph, and average splits. Predict race times for 5K, 10K, half marathon and marathon using the Riegel formula. Everything runs in your browser — no uploads, no accounts.

Time (h : m : s)

hours

min

sec

Pace / km

5:00

min per km

Pace / mile

8:03

min per mile

Speed

12.0km/h

7.5 mph

Total Time

25:00

5 km

Average Splits

1 km: 5:001 mi: 8:03

Race Time Predictions (Riegel)

5K

5:00 /km

25:00

10K

5:13 /km

52:07

Half Marathon

5:27 /km

1:55:00

Marathon

5:41 /km

3:59:47

Based on the Riegel formula (exponent 1.06). Predictions are estimates — training, terrain, and conditions matter.

Frequently Asked Questions

Everything you need to know about running pace and race predictions

How do I calculate my running pace?
Enter the distance you ran and your total time. Your pace is the time per kilometer (or mile) — for example, running 5 km in 25 minutes gives a 5:00 min/km pace. We also show speed in km/h and mph.
How accurate are the race time predictions?
We use the Riegel formula (T₂ = T₁ × (D₂/D₁)^1.06), a widely used endurance model that predicts race times from a recent race result. Predictions are most accurate when the input is a similar-distance effort. They're estimates — training, terrain, and weather all matter.
What's a good running pace for beginners?
A conversational pace (able to speak in full sentences) is a great starting point — typically 6:30–8:00 min/km for many beginners. Use our calculator to find your current pace, then build consistency before chasing speed.
Is my data private?
Yes. All calculations happen entirely in your browser. Your running data never leaves your device — no accounts, no uploads.

Share this tool

Share
Runs in your browser100% privateNo data uploaded