Miles to Kilometers for Runners: 5K, 10K, Marathon

June 12, 2025 • 4 min read

Running events are named in kilometers (5K, 10K) but many runners think in miles. Whether you are training on a treadmill set to miles or racing a metric event, here is the complete guide to distance conversions for runners.

The Conversion

Common Race Distances

• ▶ 5K = 3.107 miles (most popular entry-level race)
• ▶ 10K = 6.214 miles
• ▶ 15K = 9.321 miles
• ▶ Half Marathon = 21.0975 km = 13.109 miles
• ▶ Marathon = 42.195 km = 26.219 miles
• ▶ Ultra Marathon (50K) = 31.07 miles
• ▶ Ultra Marathon (100K) = 62.14 miles

Pace Conversion: min/km vs min/mile

Pace is where it gets tricky. Here are common running paces in both units:

• ▶ 4:00 min/km = 6:26 min/mile (elite runner)
• ▶ 5:00 min/km = 8:03 min/mile (strong amateur)
• ▶ 5:30 min/km = 8:51 min/mile (good recreational)
• ▶ 6:00 min/km = 9:39 min/mile (steady jogger)
• ▶ 7:00 min/km = 11:16 min/mile (easy pace)

Quick formula: To convert min/km to min/mile, multiply by 1.609. To go the other way, multiply min/mile by 0.621.

Using the "8 and 5" Rule

For quick mental estimates while running, remember that 8 km is roughly 5 miles. This gives you a handy multiplier:

• ▶ 5 miles done = about 8 km done
• ▶ 10 miles done = about 16 km done
• ▶ If your goal is 10K, you need to run about 6.2 miles

Treadmill Tips

Most treadmills in the US display speed in miles per hour. To match a km-based training plan:

• ▶ To run at 5:00 min/km, set the treadmill to 7.5 mph (12 km/h)
• ▶ To run at 6:00 min/km, set it to 6.2 mph (10 km/h)
• ▶ To run at 4:30 min/km, set it to 8.3 mph (13.3 km/h)

Whichever unit you prefer, the distance is the same. The finish line does not care if you counted in miles or kilometres.