Working backwards from a goal
Most run/walk calculators tell you what a ratio produces. This one answers the more useful question: given a goal time and a walking pace, what run pace does each ratio demand? A 4:30 marathon at 9:30 walking pace needs about 5:55 per kilometre during the run segments on a 4:1 cycle, or 5:30 on 2:1.
Reading the verdict column
A ratio is workable if the required run pace is slower than your 5K pace. If a ratio demands faster running than you can race 5 km, no amount of discipline will make it hold for 42 km. The verdict column marks those rows so you can move to a walking-heavy ratio instead of chasing an impossible split.
Adjusting during the race
Start with the ratio that gives the most conservative run pace, then shorten the walk break if you are ahead of schedule after 25 km. Doing it the other way round — starting ambitious and walking more later — is how run/walk plans fall apart.
Frequently Asked Questions
What ratio should a beginner use?
30:30 or 1:1. Both are easy to remember and forgiving if a walk break runs long.
Does walking pace need to be accurate?
It should be a brisk walk you can repeat all day, typically 9:00–10:00 per kilometre. A slow stroll changes the maths significantly.
Can I use this for a half marathon?
Yes — change the distance. The arithmetic is identical, though shorter races usually allow a more aggressive ratio.
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