🚀Speed Converter
Convert speed units: kilometers per hour, miles per hour, meters per second, knots and feet per second with exact definitions.
Worked examples
1 Kilometers per hour in Miles per hour
GET /api/v1/converters/speed-converter?value=1&from=kmh&to=mph
Result: 0.621371 mph
100 Kilometers per hour in Miles per hour
GET /api/v1/converters/speed-converter?value=100&from=kmh&to=mph
Result: 62.14 mph
5 Miles per hour in Kilometers per hour
GET /api/v1/converters/speed-converter?value=5&from=mph&to=kmh
Result: 8.05 km/h
2 Kilometers per hour in Meters per second
GET /api/v1/converters/speed-converter?value=2&from=kmh&to=ms
Result: 0.555556 m/s
Machine API (x402)
$0.001 / callThis tool is also a JSON API for AI agents. Requests without payment receive 402 Payment Required plus instructions; agents pay USDC on Base via the x402 protocol — no accounts, no API keys.
GET /api/v1/converters/speed-converter?value=1&from=kmh&to=mph HTTP/1.1
Host: agenttools-hub.vercel.app
→ 402 (payment required, instructions in headers)
→ 200 (after X-PAYMENT header; JSON body below)
{
"tool": "converters/speed-converter",
"input": {"value":1,"from":"kmh","to":"mph"},
"result": { "value": 0.621371, "answer": "0.621371 mph" }
}Agent docs: /llms.txt · OpenAPI spec · integration guide
About this tool
Convert road speeds, aviation and marine speeds between kilometers per hour, miles per hour, meters per second, knots and feet per second using exact unit definitions.
value × km/hfactor ÷ target factor (all units relate to the m/s base)
Frequently asked questions
How fast is 100 km/h in mph?
100 km/h ≈ 62.14 mph. The exact factor is 1 km/h = 0.621371 mph.
What is a knot?
One knot is one nautical mile (1,852 m) per hour ≈ 1.852 km/h ≈ 1.151 mph — the standard speed unit in aviation and marine navigation.
How do I convert m/s to km/h?
Multiply by 3.6. For example 30 m/s = 108 km/h.