ChaseTime

Train smarter. Race faster.

Pace Race predictor Treadmill
📊 Average Times by Age

Running Pace Calculator & Race Time Predictor

How to Use This Running Calculator

Pace Calculator

Enter any distance (km or miles) and your finish time to instantly calculate your running pace per kilometre or mile. Works for any distance — track intervals, 5K, 10K, half marathon, or full marathon.

Race Time Predictor

ChaseTime uses the Riegel formula — T2 = T1 × (D2 / D1)1.06 — to predict how fast you can race at other distances. Used by coaches worldwide to set realistic race goals.

Treadmill Speed Converter

Convert your outdoor running pace (min/km or min/mile) to the treadmill speed setting in km/h or mph. Never do the maths in your head again.

Frequently Asked Questions

How accurate is the race time predictor?
The Riegel formula is accurate within 2–5% for most runners across distances from 5K to marathon, when the reference effort is a recent, all-out race.
What is the Riegel formula?
The Riegel formula (T2 = T1 × (D2 / D1)1.06) was published by Pete Riegel in 1977. ChaseTime uses the standard exponent of 1.06 for road running.
How do I calculate my running pace?
Divide your finish time by distance — e.g. a 55-minute 10K = 5:30/km. ChaseTime calculates this instantly as you type.
What treadmill speed equals a 5:00/km pace?
5:00/km = 12.0 km/h (60 ÷ 5 = 12). Use the Treadmill tab to convert any pace instantly.
How do I predict my marathon time from a half marathon?
Enter 21.1 km and your half marathon time. ChaseTime projects your full marathon time using the Riegel formula.