Are Celsius And Centigrade The Same? | Name Rules Today

You’ll see “Celsius” on weather apps, recipes, science class notes, lab reports, and thermostat screens. You’ll also hear people say “centigrade,” especially if they learned the scale years ago or grew up with older textbooks.

If you’ve ever paused and wondered whether you’re dealing with two different scales, you’re not alone. The good news: your numbers don’t change. What changes is the name you should use when you want formal, standards-style writing.

Are Celsius And Centigrade The Same? Quick Clarity

Most of the time, yes. When a thermometer reads 25 °C, you can call that “25 degrees Celsius” or “25 degrees centigrade” and you mean the same temperature on the same scale.

The practical split is naming: “degree Celsius” is the term used in measurement standards and technical style guides, while “degree centigrade” shows up as an older, casual label. So if your question is are celsius and centigrade the same? the answer for day-to-day use is “they line up one-to-one.”

Celsius vs Centigrade: What Changes And What Doesn’t

Topic	Celsius	Centigrade
What the word points to	A named temperature scale used with the unit symbol °C	A “hundred-step” idea tied to 0 and 100 on water points
Numbers on a thermometer	Same numeric readings	Same numeric readings
Unit name in standards	“degree Celsius”	Older term; not preferred in standards writing
Symbol you’ll see	°C	Often still written as °C in practice
Where it shows up	Science, engineering, medicine, weather, daily life	Older manuals, older classroom material, casual speech
Risk of confusion	Low	Higher in formal work since “grade” is used for other units too
Best choice for reports	Use “degree Celsius” and write values as 23 °C	Avoid in reports unless a legacy document demands it
Best choice for conversation	Common and widely understood	Also understood in many places, just dated

Celsius And Centigrade Names For The Same Scale Today

Here’s the simple idea: both names point to the temperature scale where water freezes at 0 and boils at 100 under standard pressure. That “0 to 100” setup is why “centigrade” caught on as a descriptive label.

Over time, measurement bodies settled on a single name for the unit term: “degree Celsius.” You still write the same symbol (°C), and you still read the same numbers, but the preferred wording is “degrees Celsius.”

Why “Centigrade” Was A Handy Label

“Centigrade” comes from the idea of dividing the interval between two reference points into one hundred steps. In older teaching materials, it’s a neat mnemonic: centi- means one hundred, and “grade” hints at steps.

That label works fine in day-to-day talk. The snag is that “grade” has been used in other measurement contexts too, so standards bodies favored a clearer proper name.

Why “Celsius” Is The Standards Term

In 1948, the Comité International des Poids et Mesures (CIPM) chose “degree Celsius” from a short list of proposed names. You can see the wording on the official BIPM record: BIPM 1948 Adoption Of “Degree Celsius”.

This choice didn’t change the scale you use at home. It mainly cleaned up terminology in technical writing, textbooks, and standards documents that need one consistent label.

How The Scale Landed On 0 And 100

The “centi” idea is easy to remember because the scale uses a 0–100 spread between two water reference points under standard pressure. That’s also why old thermometers often printed “centigrade” right on the face.

One twist from history: early versions of the scale weren’t always oriented the way you see it now. The modern setup—0 at freezing and 100 at boiling—won out because it’s practical and easy to teach.

So when someone says “centigrade,” they’re leaning on that 100-step story. When a standards document says “degree Celsius,” it’s using the formal name for the same scale and the same unit symbol.

Where You’ll Still Hear “Centigrade”

“Centigrade” still pops up in a few places:

• Older school notes and older lab handouts.
• Dial thermometers or equipment labels printed decades ago.
• Military and aviation chatter in some regions.
• Casual talk where people grew up with the term.

If you run into it, treat it as a naming choice, not a new unit. The reading stays tied to °C.

What °C Means And How To Write It Cleanly

Even if you never write lab reports, you’ve seen the “degree sign + C” combo all over. The main formatting rules are simple and keep your writing tidy.

Spacing, Plurals, And Negative Values

• Put a space between the number and the unit symbol: 23 °C, not 23°C.
• Use “degree” for one value and “degrees” for more than one: 1 degree Celsius, 20 degrees Celsius.
• Write negative values with a minus sign: −5 °C.
• Don’t add extra words inside the symbol. Stick with °C as printed.

Standard Wording In Formal Writing

When you want the wording that matches measurement style guides, use “degree Celsius.” NIST also flags “degree centigrade” as an older term and points writers to Celsius: NIST Writing With SI Units.

That one change—choosing “Celsius” in your text—keeps reports, homework, and documentation aligned with common standards practice.

Celsius Temperature And Temperature Differences

This is the part that trips people when they jump between Celsius and Kelvin. A Celsius reading tells you a temperature on a scale with a chosen zero point. A temperature difference tells you a gap between two temperatures.

Same Step Size As Kelvin

A change of 1 °C is the same size as a change of 1 K. So if a room warms from 20 °C to 23 °C, the temperature rose by 3 °C, and that rise is also 3 K.

Zero Points Are Different

Kelvin starts at absolute zero, while Celsius sets 0 °C near the freezing point of water. So 0 °C is not “zero heat.” It’s just a chosen point on a practical scale.

Common Reference Temperatures In Celsius

If you want quick anchors for what numbers “feel like,” a short list helps more than memorizing formulas. These benchmarks also make it easier to spot typos in homework, recipes, or lab sheets.

Daily Benchmarks

People often treat 0 °C as “freezing weather,” 20–22 °C as “comfortable indoors,” and 30 °C as “hot.” Those are not lab-grade statements, yet they work as gut checks.

Physical Benchmarks

Water freezing and boiling points are classic anchors, yet boiling depends on air pressure. At higher elevations, water can boil below 100 °C. So treat 100 °C as a standard-pressure reference, not a rule that fits all kitchens.

Converting Celsius, Fahrenheit, And Kelvin Without Headaches

Most mix-ups happen when someone swaps a formula or forgets a step. The clean way is to keep each conversion as a short, repeatable routine.

Celsius To Fahrenheit

1. Multiply the Celsius value by 9.
2. Divide by 5.
3. Add 32.

Written as a formula: °F = (°C × 9/5) + 32.

Fahrenheit To Celsius

1. Subtract 32 from the Fahrenheit value.
2. Multiply by 5.
3. Divide by 9.

Written as a formula: °C = (°F − 32) × 5/9.

Celsius To Kelvin

Add 273.15 to the Celsius value: K = °C + 273.15.

Kelvin To Celsius

Subtract 273.15 from the Kelvin value: °C = K − 273.15.

Quick Checks That Catch Bad Math

• 0 °C should land at 32 °F. If it doesn’t, the steps got scrambled.
• 100 °C should land at 212 °F under the standard reference set.
• Room temperature near 20–22 °C should land near 68–72 °F.

Rounding And Reported Precision

When you write a temperature, match the digits to the tool. A kitchen thermometer that reads whole numbers doesn’t justify writing 21.37 °C. A lab probe that logs to 0.1 °C can.

Rounding is also a quiet source of conversion drift. If you convert 21.6 °C to Fahrenheit and round at each step, you can end up a degree off. Do the math first, then round once at the end.

• Pick a rounding rule up front (whole number, 0.1, or 0.01).
• Keep extra digits during conversion, then round the final value.
• When comparing readings, compare within the same rounding level.

How I Checked The Terms

I cross-checked two places that set the tone for unit names and unit writing. One is the BIPM record of the 1948 decision that picked the term “degree Celsius.” The other is NIST guidance on writing SI units, which also calls out “degree centigrade” as an older term.

I then matched the takeaways against day-to-day usage: thermometers, weather reports, and classroom material still use the same °C readings. That’s why you can treat the terms as equal in practice, then choose “Celsius” when you want standards-style wording.

Common Mix-Ups And How To Avoid Them

Celsius and centigrade align, yet a few side issues can make the topic feel messy. Fix these once and the confusion fades.

“Centigrade” Vs “Centesimal” Vs “Grad”

You might see “centesimal” or “grad” in other measurement topics, tied to angles and mapping. That overlap is one reason standards bodies preferred “degree Celsius” for temperature. In normal temperature work, stick to °C and the name “Celsius.”

Typing Without The Degree Sign

When you can’t type “°”, write “deg C” in plain text systems that don’t handle symbols well. In polished documents, use the degree sign if your editor can show it.

Mixing Up C And c

In science writing, case matters. “°C” uses a capital C. A lowercase c can mean other things in formulas. If you type units by hand, that capital letter saves headaches.

Reference Table For Fast Lookups

This table gives you a one-screen set of anchors you can use when converting, checking a sensor readout, or sanity-checking a homework answer.

Common Temperatures And Their Celsius Values

Reference Point	°C	Notes
Water freezing point	0	Classic reference point
Water boiling point	100	At standard pressure
Room temperature	20–22	Common indoor range
Human body temperature	37	Normal adult reference
Freezer setting	−18	Common food storage target
Refrigerator setting	1–4	Typical safe food range
Hot bath range	37–40	Comfort range varies by person
Warm summer day	28–32	“Hot outside” range

When To Use Each Term In School, Work, And Daily Life

If you’re writing for a class, a lab, a manual, or a report, pick “degree Celsius.” It’s the name used in standards documents and it matches what teachers and editors expect.

If you’re chatting or reading an older manual, “centigrade” can still make sense. The scale stays the same, so you can treat the word as a legacy label.

If you’re updating an older sheet that says centigrade, keep the figures and switch the label. The symbol °C already does the lifting for readers.

A Simple Rule That Rarely Fails

• Write values as numbers plus °C.
• Say “degrees Celsius” when you read it aloud.
• If someone says “centigrade,” treat it as the same reading on °C.

Quick Checklist For Clean Temperature Answers

If you just want the “do this, skip that” list, this wraps it up in one place.

• Yes, they match: Celsius and centigrade point to the same scale in practice.
• Use “degree Celsius” in writing that needs standard wording.
• Keep a space between the number and °C: 25 °C.
• Use conversion checks: 0 °C = 32 °F, 100 °C = 212 °F.
• For the original question are celsius and centigrade the same? treat centigrade as a dated label, not a different unit.