How to Convert Miles to Kilometers

4 min read•June 1, 2025•Reviewed: June 1, 2026

✓Reviewed by Apex Conversion Editorial Team · Last reviewed June 1, 2026

To convert miles to kilometers, multiply by 1.609344. For a quick estimate, multiplying by 1.6 is accurate to within 0.58% — good enough for driving distances, speed comparisons, and fitness tracking.

This conversion is needed whenever US or UK distances must be understood in metric terms: reading European road signs, following a metric training plan, or interpreting international maps.

Step-by-Step Method

Step 1: Identify the miles value. Step 2: Multiply by 1.609344 for an exact result, or by 1.6 for a quick estimate. Step 3: Round to one decimal place for most practical uses.

Example — Convert 25 miles: 25 × 1.609344 = 40.23 km. Quick estimate: 25 × 1.6 = 40 km. The shortcut gives 40 km, within 0.6% of the exact 40.23 km.

Worked Examples

Driving: road is 50 miles
  50 × 1.609344 = 80.467 km  (shortcut: 50 × 1.6 = 80 km)

Running: race is 5 miles
  5 × 1.609344 = 8.047 km  (shortcut: 5 × 1.6 = 8 km)

Speed limit: 70 mph
  70 × 1.609344 = 112.654 km/h  (shortcut: 70 × 1.6 = 112 km/h)

Trip distance: 350 miles
  350 × 1.609344 = 563.27 km

Speed Limit Conversions

Speed limits in the US are in mph; most of the world uses km/h. Common US limits and their metric equivalents: 25 mph = 40.2 km/h, 35 mph = 56.3 km/h, 45 mph = 72.4 km/h, 55 mph = 88.5 km/h, 65 mph = 104.6 km/h, 70 mph = 112.7 km/h.

When driving in Europe with a US license, GPS devices typically show km/h. Know that 100 km/h ≈ 62 mph and 130 km/h ≈ 81 mph for the two most common EU motorway limits.

Quick Tips

✓
Multiply by 1.6 for a quick estimate — accurate to within 0.6%.
✓
Double the miles and subtract 19%: 10 mi → 20 × 0.81 = 16.1 km. Accurate but complex.
✓
Simpler: multiply by 8/5 (1.6) — easy with mental fraction arithmetic.
✓
1 mile = approx 8 city blocks in US grid cities (each block ≈ 1/8 mile ≈ 200 m).