Running guides
Learn the numbers behind your running
Short, practical guides that explain what the calculators do — and how to use them to train smarter and race better.
What Is Age Grading? A Runner’s Guide to Age-Graded Scores
How age-graded percentages let a 25-year-old and a 70-year-old compare performances on a level playing field — and what your score actually means.
Read guideHow to Calculate Your Running Pace (and Actually Use It)
Pace is the number every runner lives by. Here’s how to calculate it, convert it to speed, and turn it into race splits and training zones.
Read guideRace Time Prediction Explained: Using the Riegel Formula
How a single recent result can predict your 5K, 10K, half or marathon time — and why the Riegel formula’s 1.06 fatigue factor matters.
Read guideEven vs Negative Splits: How to Pace Your Race
The difference between even, negative and positive splits — and how to plan the splits that stop you blowing up in the second half.
Read guideRunning Training Pace Zones Explained
Why most of your running should be easy, what threshold and interval pace really mean, and how to set all five zones from one number.
Read guideTreadmill Pace vs Outdoor Pace: Speed, Incline and Conversion
How to turn the treadmill’s mph or kph into a real running pace — and why a 1% incline makes it match the road.
Read guide