Centigrade to Celsius converter
25 degrees centigrade is 25 degrees Celsius: the two names describe the same scale, so the number never changes. Check a reading from an old exam paper, weather log or recipe and get it labelled in modern Celsius, with the identity shown step by step. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Centigrade
- 100
- Result
- 100 C
- Converted
- 100
- Celsius
- 100
- From unit
- centigrade
A centigrade-to-Celsius converter settles a naming question that still appears in textbooks, weather archives, laboratory notebooks, and exam papers: is a reading labelled degrees centigrade the same as degrees Celsius? By international agreement they are the same linear hundred-degree scale, so this tool returns the identical finite number, labelled as Celsius, together with a short formula, a scale factor of one, and substitution steps you can paste into a worksheet.
Why centigrade and Celsius are the same scale
The word centigrade originally named a hundred-degree interval between the freezing and boiling points of water at standard pressure. Anders Celsius first proposed a hundred-part thermometer with inverted anchors; later practice fixed zero at ice and one hundred at steam, which is the everyday metric temperature people still quote on weather maps and in school science. In 1948 the ninth General Conference on Weights and Measures adopted the name degree Celsius for that same interval, honouring Celsius while leaving the numeric marks on the glass unchanged.
A thermometer that reads twenty-five degrees centigrade therefore already reads twenty-five degrees Celsius: there is no additive offset and no five-ninths factor of the kind used when mapping Fahrenheit. Searchers still type centigrade to celsius because older exam papers, colonial-era weather logs, cooking pamphlets, and some regional style guides never dropped the older word. This capability exists for that search intent.
It does not secretly convert Fahrenheit, does not add two hundred seventy-three point fifteen to reach kelvin, and does not guess units from a free-form sentence. It applies the identity Celsius equals centigrade, documents the exact factor of one, and keeps the signed magnitude so winter negatives and cryogenic notes remain meaningful.
Practical tips, checks, and related searches
Prefer sending bare numbers when you control the client. Round-trip sanity checks are easy: convert the textbook freezing point of zero centigrade and confirm you receive exactly zero Celsius after rounding, convert one hundred and confirm one hundred Celsius, or convert a room-temperature twenty-five and compare against the identity. When teaching, pair this landing with a Fahrenheit converter so students see the difference between a rename and a genuine linear map with an offset and a five-ninths factor.
Prefer this capability when the input is already labelled centigrade and you only need the modern Celsius name and the same number. If you must convert among many temperature units in one call, use a broader temperature converter instead. Keep requests small, pin the rounded result in tests, and you get a reproducible identity for homework, LMS plugins, and edge workers without standing up a computer-algebra system of your own.
What you can do with it
Digitising historical weather logs
Map archive columns labelled degrees centigrade onto modern Celsius fields without changing magnitudes, so old station books line up with SI-named datasets.
Homework and exam-paper checks
Students confirm that a centigrade reading is already Celsius and compare the identity steps against a hidden-offset mistake they might have copied from a Fahrenheit formula.
Recipe and lab-note modernisation
Publishers rewriting older pamphlets replace the word centigrade with Celsius while keeping the same numeric setpoints for ovens, baths, and incubators.
FAQ
Are degrees centigrade the same as degrees Celsius?
Yes. They name the same hundred-degree scale (ice at 0, steam at 100). This tool returns the same finite number labelled Celsius, with factor 1.
What formula converts centigrade to Celsius?
Celsius = centigrade. There is no offset and no 5/9 factor. The 1948 CGPM rename kept the numeric interval and changed only the official name.
Is the centigrade to Celsius converter free?
The browser tool is free and runs locally.
Why was centigrade renamed Celsius?
In 1948 the ninth General Conference on Weights and Measures adopted the name degree Celsius to honour Anders Celsius. The marks on the thermometer stayed where they were, so only the label changed, never the reading.
Do negative centigrade readings stay negative in Celsius?
Yes. The sign is kept, so minus 5 degrees centigrade is minus 5 degrees Celsius. Winter temperatures and cold-lab notes keep their meaning, because nothing is added or multiplied along the way.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/conv/centigrade-to-celsius \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"centigrade":100}'const res = await fetch("https://api.kit.forhosting.com/conv/centigrade-to-celsius", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"centigrade": 100
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/centigrade-to-celsius",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"centigrade": 100
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/centigrade-to-celsius", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"centigrade":100}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"centigrade":100}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/centigrade-to-celsius", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"centigrade": 100
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.centigrade_to_celsius",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_abs | 1000000000000 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Enter a finite temperature in degrees centigrade; the solver rejects missing fields, non-numeric strings, NaN, and infinities with invalid_input instead of inventing a result.
Why centigrade and Celsius are the same scale
Teachers can show the CGPM rename beside the JSON so students stop looking for a hidden conversion table that does not exist.
How to call the API and what comes back
Absolute values must stay within the published limit of one trillion. Send a JSON body with one required finite number field named centigrade. Aliases value, temperature, temp, deg_c, and c are accepted so SDK clients and form posts can use the name that fits the product. On success the response echoes rounded centigrade, sets celsius, result, and converted to the same rounded Celsius magnitude, unit to the token C, from_unit to centigrade and to_unit to C, factor to one, identical to true, formula to the string celsius equals centigrade, message to a short English summary, and steps to an ordered array of substitution lines that show the identity map. Failed validation—missing fields, non-finite numbers, bare plus or minus signs, non-numeric strings, or values outside absolute limits—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item. Prefer a JSON number when you control the client; numeric strings are accepted only when they match a strict finite pattern without degree symbols, unit letters, or thousand separators. Do not send Fahrenheit or kelvin through this endpoint expecting an implicit scale guess: that would silently mislabel a reading, which is worse than a typed error the caller can catch and correct.
Practical tips, checks, and related searches
Stay inside the absolute range so the identity cannot be asked to echo a non-finite IEEE value the solver must reject. This landing targets people searching for centigrade to celsius, convert degrees centigrade to Celsius, or whether centigrade and Celsius are the same; it is not a general multi-scale temperature hub, not a Fahrenheit-to-Celsius primary form, and not a kelvin or gas-mark converter. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately omit centigrade or pass text. Archive and museum projects can batch old centigrade logs through the API at $0.002 per successful item and store the echoed Celsius field without rewriting magnitudes.
Technical questions
Can I convert Fahrenheit or Kelvin with this tool?
No. Input is always degrees centigrade. Use a dedicated Fahrenheit or Kelvin converter if the source scale is different; this endpoint will not guess units.
What happens on missing or non-numeric input?
The API returns invalid_input naming the problem (for example a missing centigrade field or a non-finite value). Failed tasks are not charged.