CALTRX

Kilometers to Miles

Convert kilometers to miles. 1 km = 0.621371 miles. For US road distances, speed limits, and running.

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Miles

Tips & Notes

  • ✓Quick mental math: multiply km by 0.6 for approximate miles (error: 3.5%). Better: km × 5 ÷ 8.
  • ✓Speed limits: 100 km/h = 62.1 mph, 120 km/h = 74.6 mph, 130 km/h = 80.8 mph.
  • ✓Running: 5 km = 3.11 miles, 10 km = 6.21 miles, 21.1 km (half marathon) = 13.11 miles.
  • ✓Fuel economy: L/100km to mpg requires a different formula (not just × 0.621).

Common Mistakes

  • ✗Using 0.6 instead of 0.621371 — a 3.1% underestimate for large distances.
  • ✗Confusing km/h with mph — 100 km/h is 62 mph, not 100 mph.
  • ✗Confusing nautical miles (1.852 km) with statute miles (1.609 km).
  • ✗Assuming European speed limits in mph — they are in km/h. 130 km/h ≠ 130 mph.

Kilometers to Miles Overview

What This Calculator Does

Converts kilometers to statute miles: 1 km = 0.621371 miles (= 1 ÷ 1.609344 exactly).

Speed and Distance Reference

| km/h | mph | km | miles | |------|-----|----|-------| | 50 | 31.1 | 10 | 6.21 | | 100 | 62.1 | 42.2 | 26.2 | | 120 | 74.6 | 100 | 62.1 | | 130 | 80.8 | 1,000 | 621 |

Running Distances

5K = 3.107 miles. 10K = 6.214 miles. Half marathon = 21.097 km = 13.109 miles. Marathon = 42.195 km = 26.219 miles.

Quick Mental Estimate

Multiply km by 0.6 for a rough mph equivalent (exact is 0.621). Error is under 3.5% — acceptable for casual estimation. For navigation and official use, always apply the full 6-decimal factor.

Frequently Asked Questions

100 × 0.621371 = 62.14 miles. A common road distance or race distance.

42.195 × 0.621371 = 26.22 miles. This is the official marathon distance.

1 km = 0.621371 miles — roughly 0.62 miles or about 5/8 of a mile.

100 × 0.621371 = 62.14 mph. The common European highway speed limit of 100 km/h equals about 62 mph.