5K, 10K, Half & Full Marathon Distances in Miles and KM
A clear reference for common running race distances — 5K, 10K, half marathon, and marathon — in both miles and kilometers, plus typical finish times.
May 15, 2026 · 2 min read
The four most common road race distances are the 5K (3.1 miles / 5 km), 10K (6.2 miles / 10 km), half marathon (13.1 miles / 21.1 km), and marathon (26.2 miles / 42.2 km). Each step up is roughly double the previous, creating a natural ladder runners climb as their fitness and ambition grow.
The distances at a glance
- 5K — 3.1 miles / 5 kilometers — the most popular entry race.
- 10K — 6.2 miles / 10 kilometers — a fast, demanding step up.
- Half marathon — 13.1 miles / 21.1 kilometers — endurance meets speed.
- Marathon — 26.2 miles / 42.2 kilometers — the classic endurance milestone.
- Ultramarathon — anything beyond 26.2 miles, often 50K, 50 mi, 100K, or 100 mi.
Typical finish times
Finish times vary enormously, but as rough guides: a 5K takes most people 20–40 minutes, a 10K 45–75 minutes, a half marathon 1.5–2.5 hours, and a marathon 3.5–6 hours. Beginners land at the slower end and improve quickly with consistent training.
Which distance should you choose?
- New to running: start with a 5K — achievable and motivating.
- Running 10–15 miles a week: a 10K is a great next challenge.
- Comfortable with a 5-mile long run: build toward a half marathon.
- Consistently running 20+ miles a week: a marathon is within reach with a proper plan.
Don't skip the ladder
It's tempting to jump straight to the marathon, but progressing through the shorter distances builds durability, race experience, and speed that make your eventual marathon far more enjoyable.
Frequently asked questions
How many miles is a half marathon?
A half marathon is 13.1 miles, or 21.1 kilometers — exactly half of a full marathon.
Is a 10K twice as hard as a 5K?
It's twice the distance but not necessarily twice as hard, because a 10K is run at a slightly slower pace. With proper training, runners comfortable at 5K can progress to 10K within a few weeks.
What distance should a beginner start with?
Most beginners should start with a 5K. It's challenging enough to be meaningful but achievable in about eight weeks of training, even from a non-running starting point.
Put it into practice
Let Coach Ben build your plan.
Stride turns this advice into a real periodized plan — pace targets, live GPS, audio coaching, and auto PRs from 5K to ultra.
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