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Convert kilometers to miles instantly with our accurate calculator. Perfect for travel planning, running distances, driving routes, and international navigation.
Try: 1, 5, 10, 42.2, 100, 160, etc.
Formula: kilometers × 0.621371 = miles
Exact: 10 × 0.621371 = 6.214 mi
Handy Rule: 160 km ≈ 100 miles (useful for trip planning)
| Kilometers | Miles | Context |
|---|---|---|
| 1 km | 0.62 mi | One kilometer exactly |
| 5 km | 3.11 mi | 5K run or short drive |
| 10 km | 6.21 mi | 10K run or city distance |
| 21.1 km | 13.11 mi | Half marathon distance |
| 42.2 km | 26.22 mi | Full marathon distance |
| 50 km | 31.07 mi | Medium-distance drive |
| 100 km | 62.14 mi | Long-distance drive or 100K race |
| 160 km | 99.42 mi | Approximately 100 miles |
| 200 km | 124.27 mi | Regional travel distance |
| 500 km | 310.69 mi | Cross-country segment |
| 1000 km | 621.37 mi | Major intercity distance |
| 1609 km | 1000 mi | Exactly 1000 miles |
The conversion factor from kilometers to miles is 1 kilometer = 0.621371 miles (more precisely 0.621371192). This derives from the exact international definition where 1 mile equals 1.609344 kilometers. Taking the reciprocal: 1 ÷ 1.609344 = 0.621371192 miles per kilometer. For most practical travel and navigation purposes, using 0.621 or even 0.62 provides sufficient accuracy. GPS navigation typically uses 0.6214 for balance between precision and simplicity. This defined relationship ensures consistent global measurements for travel, athletics, and international distance specifications.
Basic Formula:
miles = kilometers × 0.621371
Example:
100 kilometers × 0.621371 = 62.1371 miles
For quick estimation, multiply kilometers by 0.6 (or multiply by 6 and divide by 10). Example: 50 km × 0.6 = 30 miles (actual: 31.07). Better accuracy: multiply by 5/8 gives excellent approximation (50 × 5 = 250, ÷ 8 = 31.25 miles). Remember useful benchmarks: 5 km ≈ 3 miles, 10 km ≈ 6 miles, 100 km ≈ 62 miles, and importantly, 160 km ≈ 100 miles (actually 99.42). This last rule helps quick trip planning—320 km ≈ 200 miles, 480 km ≈ 300 miles. These shortcuts verify calculations and provide ballpark figures for travel planning.
Question: How far is a 5-kilometer race in miles?
Solution:
Question: A road trip is 250 kilometers. Convert to miles.
Solution:
Question: A marathon is 42.195 km. How many miles?
Solution:
When traveling internationally, road signs in most countries display distances in kilometers while US travelers think in miles. Converting helps estimate driving time, fuel needs, and trip duration. European highway signs showing "Paris 250 km" translate to 155 miles—helping Americans gauge travel time at familiar speeds. GPS devices offer unit selection, but understanding conversions helps verify navigation, interpret local directions, and communicate with locals about distances. Rental car odometers may show kilometers, requiring conversion to track mileage limits. Understanding both systems makes international driving less confusing and helps accurate trip planning.
Running races worldwide use metric distances—5K (3.1 mi), 10K (6.2 mi), half marathon (21.1 km / 13.1 mi), marathon (42.2 km / 26.2 mi). American runners must understand both systems to train properly, set realistic goals, and compare performances. Training apps display either unit, but understanding conversions helps follow international training plans, participate in foreign races, and compare times with global runners. Track workouts measure in meters (400m lap = 0.25 mi approximately), requiring mental conversion skills. Elite runners fluently "think" in both systems, instantly converting pace and distance for optimal training and racing strategy.
Speed limits abroad display in km/h, not mph. Common conversions prevent speeding tickets: 50 km/h ≈ 31 mph (residential), 80 km/h ≈ 50 mph (rural roads), 100 km/h ≈ 62 mph (highways), 120-130 km/h ≈ 75-81 mph (European motorways). Car speedometers show both scales, but knowing conversions helps judge appropriate speed quickly. Digital displays toggle units, but analog gauges require reading the correct scale. Understanding these conversions prevents dangerous over-speeding or frustrating under-speeding when driving internationally. Most speed-related accidents involving foreign drivers stem from misunderstanding posted limits.
Cycling computers and GPS devices track distance in selectable units, but maps, race courses, and group rides may specify kilometers. Converting helps plan ride duration, nutrition timing, and pacing strategies. Mountain biking trails, hiking routes, and adventure races increasingly use metric distances globally. Understanding conversions helps estimate elevation gain per distance, calculate pace for multi-day treks, and communicate plans with international participants. Popular cycling events like Gran Fondos specify 100 km (62 miles) or 160 km (100 miles) courses, requiring conversion knowledge for training and preparation.
While aviation primarily uses nautical miles, ground distance references often appear in kilometers or statute miles. Flight planning, alternate airport selection, and fuel calculations may require km-to-miles conversion. Maritime navigation uses nautical miles for distance at sea but kilometers for coastal references and port approaches. Understanding conversions helps pilots and mariners coordinate with ground transportation, communicate with international air traffic control, verify GPS waypoints, and ensure fuel planning accuracy. Cross-referencing charts in different units requires confident conversion skills.
Multiply the kilometer value by 0.621371 (approximately 0.62 for quick estimates). Example: 10 km × 0.621371 = 6.21371 miles. This factor comes from 1 mile = 1.609344 km (reciprocal gives 0.621371). Essential for international travel, reading foreign road signs, converting GPS distances, and understanding metric speed limits. Use our calculator for instant accurate results.
The exact factor is 1 kilometer = 0.621371192 miles, derived from 1 mile = 1.609344 km. Most purposes use 0.621 or 0.62 for sufficient accuracy. Navigation and GPS use 0.6214 for better precision. Scientific calculations may need full precision (0.621371192). This internationally-defined relationship ensures consistent global measurements with zero ambiguity in technical applications.
Most countries adopted metric (kilometers) through government mandate for decimal simplicity and standardization. The US, UK (partially), and few others retained miles due to cultural tradition, infrastructure costs (millions of road signs, speedometers), and lack of mandate. Britain uses kilometers for most purposes but retains miles for roads. This divide creates ongoing need for conversion skills in travel, GPS, athletics, and commerce.
Multiply kilometers by 0.6 (or by 6, divide by 10). Example: 50 km × 0.6 = 30 miles (actual: 31.07). Better: multiply by 0.62. Most accurate: multiply by 5/8 (50 × 5 = 250, ÷ 8 = 31.25). Benchmarks: 5 km ≈ 3 mi, 10 km ≈ 6 mi, 100 km ≈ 62 mi, 160 km ≈ 100 mi. Use exact 0.621371 for important distances.
5 kilometers equals approximately 3.107 miles (commonly 3.1 miles). Calculation: 5 × 0.621371 = 3.106855 miles. This popular race distance helps runners set pace goals and compare training distances. A 10-minute-per-mile pace for 3.1 miles equals approximately 31 minutes total. Understanding this conversion is fundamental for international races or following metric training plans.
A marathon is exactly 42.195 kilometers, equaling 26.219 miles (26 miles 385 yards, or 26.2 miles). This standard distance was established in 1921. Conversion: 42.195 × 0.621371 = 26.21876 miles. International marathons advertise in kilometers; US marathons emphasize miles. Understanding both systems helps with pacing strategies, nutrition planning, and comparing performance across races.
Transportation/logistics (international shipping), automotive (importing vehicles), aviation (flight distances), tourism (trip planning), GPS/mapping services, athletic event management, cycling, hiking guides, emergency services (cross-border operations), military (international deployments), maritime navigation, weather services (storm tracking), and astronomy. Even domestic US industries encounter metric specifications from international partners, ISO standards, or global supply chains, making conversion essential.
Modern speedometers display dual scales—outer ring showing km/h, inner showing mph (or vice versa). US cars emphasize mph; European cars emphasize km/h. Digital displays toggle via settings. Imported vehicles may show only metric. Canadian speedometers show both since Canada uses km/h but borders the US. Understanding conversion prevents speeding tickets abroad—100 km/h equals 62 mph, a common highway limit difference.
Depends on application. Casual travel can round to 0.6 (~3% error). GPS uses 0.621 for precision/simplicity balance. Athletic timing uses 0.6214 or higher. Scientific research, surveying, and legal specs require full precision (0.621371192). Aviation needs high accuracy for fuel calculations. When uncertain, use higher precision—round later. For critical work, verify independently and consult relevant authorities.
Yes! The same factor converts distance and speed—time units cancel out. Multiply km/h by 0.621371 to get mph. Example: 100 km/h = 62.1371 mph. Common conversions: 50 km/h ≈ 31 mph, 80 km/h ≈ 50 mph, 120 km/h ≈ 75 mph. Understanding these helps when driving internationally. Most countries post limits in km/h (European highways 130 km/h ≈ 81 mph).
160 kilometers equals 99.42 miles—very close to 100. Useful benchmark for quick conversions: 160 km ≈ 100 mi, 80 km ≈ 50 mi, 40 km ≈ 25 mi. Calculation: 160 × 0.621371 = 99.41939 miles. Many travelers use this rule for estimating distances abroad. A 320 km drive equals approximately 200 miles. While not exact, it provides reasonable accuracy for trip planning and fuel estimation.
Converting pace inverts distance conversion. If running 5:00 min/km, this equals approximately 8:03 min/mile (multiply by 1.609344). Conversely, 8:00 min/mile equals about 4:58 min/km (multiply by 0.621371). Understanding both helps follow international training plans and compare performance. Marathon pace planning: a 4-hour marathon requires 5:41 min/km or 9:09 min/mile pace. Many runners learn both systems for flexibility.
Using 0.5 instead of 0.621 (creates ~20% error), confusing km-to-miles with miles-to-km (should multiply by 0.621, not 1.609), mixing distance and area conversions (square km need different factor), assuming 100 km = 60 mi (actually 62.14), rounding too early, confusing statute with nautical miles. Avoid by clearly writing conversion factor, using calculator, verifying direction, checking against benchmarks, maintaining precision before final rounding.
GPS calculates distances mathematically from coordinates regardless of units, then converts for display based on user settings. Most devices offer unit preference (km or miles). Underlying calculation uses meters or decimal degrees, then converts to selected display units. Smartphones detect region automatically (km in Europe, miles in US) but allow manual override. Apps like Google Maps respect unit preferences. Understanding both helps verify accuracy internationally.
Best practice: work in the unit system most relevant to your context. If traveling in Europe, think in kilometers to match road signs. If planning in the US, work in miles. Converting introduces errors, especially through multiple calculations. Modern tools handle both simultaneously, but understanding local standards helps with practical navigation. For international communication, provide both units. When possible, use tools displaying both simultaneously.
This calculator provides mathematical conversions for informational purposes. While we use the internationally defined conversion factor (1 km = 0.621371 miles), always verify important distances independently. For navigation, use official GPS devices and maps. For athletic events, refer to official race distances. Speed conversions are provided for reference—always obey posted speed limits in the local measurement system.