Speed Converter

The Speed Converter converts between different speed measurement units. It provides three conversion tabs: km/h↔mph, m/s↔km/h, and m/s↔mph. Kilometers per hour (km/h) is the standard unit for road speed in most countries, including Korea, Europe, and most of Asia. Miles per hour (mph) is used in the United States, the United Kingdom, and a few other countries for road speed. Meters per second (m/s) is the SI unit of speed used in science and engineering. Understanding speed conversions is essential for international driving (speed limits vary by unit system), sports (world records, ball speeds), weather (wind speeds), aviation, and scientific calculations. For example, knowing that Korea's highway speed limit of 110 km/h equals about 68 mph helps international visitors understand local traffic rules. The converter provides instant bidirectional conversion between all three units, making it useful for travelers, sports enthusiasts, pilots, and anyone working with speed data from different international sources.

1. Select a conversion tab. • km/h ↔ mph: Most common for road speeds and everyday use. • m/s ↔ km/h: Useful for science and weather (wind speeds often in m/s). • m/s ↔ mph: Combines metric scientific with imperial everyday units. 2. Enter a speed value in either field. Type a number and the conversion appears instantly. Common Examples: • Walking speed: 5 km/h = 3.1 mph = 1.39 m/s • City speed limit (Korea): 60 km/h = 37.3 mph • Highway speed (Korea): 110 km/h = 68.4 mph • US Interstate speed: 65 mph = 104.6 km/h • Speed of sound: 343 m/s = 1,235 km/h = 767 mph • Usain Bolt top speed: 12.27 m/s = 44.17 km/h = 27.44 mph Tip: Korean speed limits are in km/h. Common limits: 30 km/h (school zones), 60 km/h (city), 80 km/h (urban highway), 100-110 km/h (expressway).

■ km/h ↔ mph 1 mph = 1.609344 km/h (exact) 1 km/h = 0.621371 mph Formula: mph = km/h ÷ 1.609344 Formula: km/h = mph × 1.609344 Example: 100 km/h = 100 ÷ 1.609 = 62.14 mph Example: 60 mph = 60 × 1.609 = 96.56 km/h ■ m/s ↔ km/h 1 m/s = 3.6 km/h (exact) 1 km/h = 0.27778 m/s Formula: km/h = m/s × 3.6 Formula: m/s = km/h ÷ 3.6 Example: 30 m/s = 30 × 3.6 = 108 km/h Example: 90 km/h = 90 ÷ 3.6 = 25 m/s ■ m/s ↔ mph 1 m/s = 2.23694 mph 1 mph = 0.44704 m/s (exact) Formula: mph = m/s × 2.23694 Formula: m/s = mph × 0.44704 Example: 10 m/s = 10 × 2.237 = 22.37 mph Example: 100 mph = 100 × 0.447 = 44.7 m/s ■ Other Speed Units 1 knot = 1.852 km/h = 1.151 mph = 0.5144 m/s Mach 1 (speed of sound at sea level) ≈ 343 m/s ≈ 1,235 km/h ≈ 767 mph ■ Speed Limit Quick Reference 30 km/h = 18.6 mph | 50 km/h = 31.1 mph | 80 km/h = 49.7 mph 100 km/h = 62.1 mph | 120 km/h = 74.6 mph | 130 km/h = 80.8 mph

■ Quick Mental Conversion • km/h to mph: Multiply by 0.6 (or multiply by 6, drop last digit). 100 km/h ≈ 60 mph. • mph to km/h: Multiply by 1.6. 60 mph ≈ 96 km/h. • m/s to km/h: Multiply by 3.6. 10 m/s = 36 km/h. • km/h to m/s: Divide by 3.6. 72 km/h = 20 m/s. ■ International Speed Limits • Korea: City 60 km/h, Highway 100-110 km/h, School zone 30 km/h • US: City 25-35 mph (40-56 km/h), Highway 55-75 mph (89-121 km/h) • Germany (Autobahn): Advisory limit 130 km/h, some sections unlimited • UK: City 30 mph (48 km/h), Motorway 70 mph (113 km/h) • Japan: City 40 km/h, Expressway 100-120 km/h ■ Sports Speed References • Fastest human (Usain Bolt): 44.17 km/h (27.44 mph) • Baseball fastball: 150-165 km/h (93-103 mph) • Tennis serve (record): 263 km/h (163 mph) • Golf drive: 250-320 km/h (155-200 mph) • Soccer free kick: 130-210 km/h (80-130 mph) ■ Wind Speed Beaufort Scale • Calm: 0-1 km/h | Light breeze: 6-11 km/h • Moderate: 20-28 km/h | Strong: 39-49 km/h • Storm: 89-102 km/h | Hurricane: 118+ km/h ■ Common Mistakes • Don't confuse knots (nautical) with km/h or mph • Speed of sound varies with altitude and temperature • UK uses mph despite being in Europe (which uses km/h)