🌡️Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin with exact formulas, reference points (freezing and boiling water) and step-by-step working.
Worked examples
20 °C in Fahrenheit
GET /api/v1/converters/temperature-converter?value=20&from=c&to=f
Result: 68 °F
98.6 °F in Celsius
GET /api/v1/converters/temperature-converter?value=98.6&from=f&to=c
Result: 37 °C
300 K in Celsius
GET /api/v1/converters/temperature-converter?value=300&from=k&to=c
Result: 26.85 °C
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/temperature-converter?value=20&from=c&to=f HTTP/1.1
Host: agenttools-hub.vercel.app
→ 402 (payment required, instructions in headers)
→ 200 (after X-PAYMENT header; JSON body below)
{
"tool": "converters/temperature-converter",
"input": {"value":20,"from":"c","to":"f"},
"result": { "value": 68, "answer": "68 °F" }
}Agent docs: /llms.txt · OpenAPI spec · integration guide
About this tool
Three temperature scales, exact conversions: Celsius for everyday metric use, Fahrenheit for US weather and cooking, Kelvin for science. Reference points and formulas are shown with every result.
°F = °C × 1.8 + 32 · K = °C + 273.15
Frequently asked questions
At what temperature are Celsius and Fahrenheit equal?
−40° — minus 40 Celsius and minus 40 Fahrenheit are the same temperature.
Why does Kelvin have no degree sign?
Kelvin is an absolute scale starting at absolute zero; by SI convention its values are written as K, not °K.
What is absolute zero in Fahrenheit?
Absolute zero (0 K) is −273.15 °C, which equals −459.67 °F.