Miles to KM Conversion: Formula, Speed Converter & Reference

Miles and kilometers are the two dominant distance units worldwide. The US, UK (partially), and Myanmar use miles, while the rest of the world uses kilometers. Whether you’re traveling abroad, following international race results, or interpreting speed limits, here’s how to convert accurately.

The Conversion Formula

Kilometers = Miles × 1.60934
Miles = Kilometers × 0.62137

Quick approximation: Multiply miles by 1.6 for a fast estimate (accurate to within 0.6%).

Examples:

• 1 mile = 1.609 km
• 5 miles = 8.047 km
• 26.2 miles = 42.165 km (marathon)
• 100 km = 62.14 miles

Common Distances in Miles and Kilometers

Distance	Miles	Kilometers
City block (average)	0.05–0.1	0.08–0.16
Quarter mile (track)	0.25	0.402
Half mile	0.5	0.805
5K race	3.107	5.0
10K race	6.214	10.0
Half marathon	13.109	21.097
Full marathon	26.219	42.195
Ultra marathon (50K)	31.069	50.0
100-mile ultra	100.0	160.934
New York to Boston	215	346
London to Paris	283	456
LA to San Francisco	382	615

The Fibonacci shortcut: Because the mile-to-km ratio (1.609) is close to the golden ratio (1.618), consecutive Fibonacci numbers approximate mile/km conversions. 5 miles ≈ 8 km, 8 miles ≈ 13 km, 13 miles ≈ 21 km. This works remarkably well for mental math.

Speed Conversion: MPH to KM/H

km/h = mph × 1.60934
mph = km/h × 0.62137

MPH	KM/H	Common Context
5	8.0	Brisk walking
10	16.1	Casual cycling
15	24.1	Fast cycling
25	40.2	School zone (US)
30	48.3	City driving (US)
50	80.5	~Highway (Europe: 80 km/h)
55	88.5	US highway
60	96.6	~100 km/h speed limit
65	104.6	US interstate
70	112.7	~110 km/h motorway
75	120.7	~120 km/h autostrada
100	160.9	~160 km/h (autobahn advisory)

Practical tip for driving abroad: The most common non-US speed limits are 50 km/h (city, ≈31 mph), 80–90 km/h (rural, ≈50–56 mph), and 110–130 km/h (highway, ≈68–81 mph).

Marathon and Running Distances

For runners, these conversions come up constantly:

Race	Official Distance	The Other Unit
5K	5.0 km	3.107 miles
10K	10.0 km	6.214 miles
15K	15.0 km	9.321 miles
Half Marathon	21.0975 km	13.109 miles
Marathon	42.195 km	26.219 miles
50K Ultra	50.0 km	31.069 miles

A common mistake: the marathon is not exactly 26.2 miles — it’s 26 miles and 385 yards (26.219 miles or 42.195 km). That extra 0.019 miles matters when you’re calculating precise pace targets.

Pace conversion: If you run a 5:00 min/km pace, that’s 8:03 per mile. Multiply your min/km pace by 1.609 to get min/mile.

Calculate instantly with our Miles to KM Converter.