MPH to KPH Calculator
Instant speed converter: mph ↔ km/h ↔ m/s ↔ knots — with UK speed limits reference
Last updated: February 2026 — by Mustafa Bilgic (MB)
Speed Converter: MPH ↔ KPH
Enter any speed value to instantly convert between mph, km/h, m/s and knots.
UK Speed Limits: MPH and KPH
| Road Type | mph | km/h | m/s | Notes |
|---|---|---|---|---|
| Residential / school zone | 20 | 32.2 | 8.9 | Common in cities |
| Built-up area (default) | 30 | 48.3 | 13.4 | Most UK towns |
| Single carriageway | 60 | 96.6 | 26.8 | National speed limit |
| Dual carriageway / motorway | 70 | 112.7 | 31.3 | Max UK road limit |
| Towing (motorway) | 60 | 96.6 | 26.8 | Caravans, trailers |
| Goods vehicles (>7.5t, motorway) | 60 | 96.6 | 26.8 | HGV limit |
MPH to KPH Speed Table (10–200 mph)
| mph | km/h | m/s | mph | km/h | m/s |
|---|
How to Convert MPH to KPH
Miles per hour (mph) and kilometres per hour (km/h or kph) are both units of speed, measuring the distance travelled in one hour. The conversion between them is based on the exact relationship between miles and kilometres: 1 international mile = 1.609344 kilometres. Therefore, 1 mph = 1.60934 km/h (to 5 decimal places).
MPH to KPH Formula:
km/h = mph × 1.60934
Example: 70 mph × 1.60934 = 112.654 km/h
KPH to MPH Formula:
mph = km/h ÷ 1.60934
Example: 100 km/h ÷ 1.60934 = 62.137 mph
UK Speed Limits: A Complete Guide
The United Kingdom uses miles per hour (mph) for all road speed measurements, enforced by law under the Road Traffic Regulation Act 1984. Speed limit signs are mandatory for all drivers in England, Scotland, Wales and Northern Ireland. Understanding UK speed limits is essential both for UK residents and for foreign visitors driving in Britain.
The current UK speed limits are:
- 20 mph (32 km/h) — Residential zones, near schools, many city centres. Becoming increasingly common in urban areas.
- 30 mph (48 km/h) — Default speed limit in built-up areas with street lighting. The most common UK speed limit.
- 40 mph (64 km/h) — Some A-roads and busier urban routes where a 30 limit would be too restrictive.
- 50 mph (80 km/h) — Some A-roads and bypass roads, also used as a variable limit on smart motorways.
- 60 mph (97 km/h) — National speed limit on single carriageways and for vehicles towing trailers on motorways.
- 70 mph (113 km/h) — National speed limit on motorways and dual carriageways. The maximum legal speed in the UK.
Converting Speed for European Travel
When driving in continental Europe, all speed limits are in kilometres per hour (km/h). A UK driver used to 70 mph motorways should know that 120 km/h (74.6 mph) is a common European motorway limit, and 130 km/h (80.8 mph) applies on some French and German autobahns. The 50 km/h (31 mph) limit is standard in most European towns and villages, equivalent to roughly 30 mph in the UK.
Key European speed limit conversions for UK drivers:
European urban limit
European rural road
European A-road
Common motorway limit
France/Italy motorway
Some German sections
Knots: Speed at Sea and in the Air
The knot is a unit of speed equal to one nautical mile per hour. It is used internationally in maritime navigation, aviation, and meteorology. One knot equals 1.852 km/h or 1.15078 mph. The term comes from the historical practice of measuring ship speed by counting the knots on a rope thrown overboard over a fixed time period.
Practical knot conversions:
- 5 knots = 5.75 mph = 9.26 km/h (small sailing boat speed)
- 20 knots = 23 mph = 37 km/h (ferry speed)
- 500 knots = 575 mph = 926 km/h (commercial aircraft cruise speed)
- Wind: 10 knots = 11.5 mph = 18.5 km/h (a "moderate breeze" on the Beaufort scale)
How to Convert MPH to KPH
This converter provides instant, accurate results for your measurement conversions. The UK uses a mix of metric and imperial measurements in daily life, which can make conversions a frequent necessity. Road signs use miles, food is sold in grams and kilograms, and height is often quoted in feet and inches despite the metric system being the official standard.
Understanding the conversion formula helps verify results and perform quick mental calculations when a tool is not available.
Key Information
Common UK conversion factors: 1 inch = 2.54 cm, 1 foot = 30.48 cm, 1 mile = 1.609 km, 1 pound (lb) = 0.4536 kg, 1 stone = 6.35 kg, 1 pint (UK) = 568 ml, 1 gallon (UK) = 4.546 litres, 1 acre = 0.4047 hectares. Temperature conversions use the formula: Celsius = (Fahrenheit - 32) x 5/9.
Example Calculation
To convert 5 feet 10 inches to centimetres: first convert to total inches (5 x 12 + 10 = 70 inches), then multiply by 2.54 to get 177.8 cm. For weight, a person weighing 12 stone 7 lbs is 12.5 stone, which equals 79.4 kg (12.5 x 6.35).
Source: Based on international measurement standards. Last updated March 2026.
Frequently Asked Questions
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