Are Centigrade And Celsius The Same? | Name Swap Rules

If you’ve ever typed “are centigrade and celsius the same?” and felt silly after, you’re not alone. The two words get tossed around like they’re rivals, yet your thermometer won’t care which one you say.

This page clears it up fast, then gets practical: what the names mean, why “Celsius” is the safer label in school and work, how to write °C correctly, and where “centigrade” can trip you up.

Are Centigrade And Celsius The Same?

Yes. In everyday temperature use, “centigrade” and “Celsius” refer to the same scale: 0° at water’s freezing point and 100° at water’s boiling point, under the usual reference pressure used in basic science teaching.

The difference is the name, not the numbers. “Centigrade” is an older label that describes the 100-step spacing between those two reference points. “Celsius” is the modern, standards-backed name for the scale and the unit wording used in formal writing.

What Centigrade Means In Plain Terms

Break the word apart and it gives away its idea: “centi” points to one hundred, and “grade” points to steps. So centigrade is the “hundred-step” scale between freezing and boiling water.

That logic made it popular in textbooks, kitchen charts, and weather reports for decades. You’ll still hear it in casual speech, and you’ll still see it printed on older dials and manuals.

Where Celsius Comes From

Celsius comes from Anders Celsius, the Swedish astronomer who proposed a temperature scale in the 1700s. Early versions of the scale flipped the endpoints compared with what we use now. Later, the direction was set to the familiar form where 0 is freezing and 100 is boiling.

Once the scientific world started tightening unit names and symbols, “degree Celsius” became the chosen label in standards and reference works. That shift is why modern lab reports, engineering notes, and most school rubrics expect “°C” and the word “Celsius.”

Centigrade And Celsius Side-By-Side Checks

Item	Centigrade	Celsius
What it points to	Name of the 100-step idea	Name tied to Anders Celsius
Scale used on thermometers	Same scale	Same scale
Freezing point of water	0°	0 °C
Boiling point of water	100°	100 °C
Preferred term in standards	Rare in modern standards text	“degree Celsius” is used
Unit symbol you should write	Often printed as °C anyway	°C
Where you still see it	Older books, older devices	Science, school, weather apps
Main risk	Can be read as an angle unit in surveying	Little confusion in temperature context
Best choice for assignments	Use only if asked	Use by default

Centigrade And Celsius In Standards, Labels, And Apps

Kelvin (K) is the SI base unit for thermodynamic temperature, and °C is built to match its step size. One change of 1 °C is the same size as a change of 1 K. So when a lab note says the sample warmed by 5 °C, you can treat that interval as 5 K too.

What changes is the zero point. Kelvin starts at absolute zero. Celsius sets zero near the freezing point of water, so daily temperatures land on handy numbers. That’s why weather apps stick to °C, while physics classes often pair °C with K.

Why 0 And 100 Work As Anchors, Not Perfect Constants

In class, you learn that water freezes at 0 °C and boils at 100 °C. That’s a solid mental anchor, yet the real world is a bit messier. Add salt, change the air pressure, or climb a mountain and the exact points shift. Even “pure water” depends on how clean the sample is and how you measure it.

That’s why modern metrology ties the degree Celsius to the kelvin, not just to a pot of water. The step size stays fixed, and reference points are handled through agreed measurement scales, like the International Temperature Scale of 1990 (ITS-90), used to keep thermometers aligned.

Why Older Tools Still Say Centigrade

A lot of older thermometers, ovens, and machine panels were labeled when “centigrade” was common in English. Makers sometimes kept the word on the faceplate even while printing the symbol °C, since people recognized the term.

If you’re reading a manual that says “centigrade,” treat it as Celsius unless the same manual is talking about angles or surveying marks. In normal household and lab temperature work, the scale is the same.

When Centigrade Can Mean An Angle Unit

Here’s the sneaky bit: in land surveying and some older engineering notes, “centigrade” can refer to a circle split into 400 parts (gradians), not a temperature scale. That’s a different topic from degrees Celsius, yet the shared word can spark mix-ups in mixed documents.

If the page is full of bearings, maps, or the number 400 tied to a circle, pause. If it’s full of thermometers, weather, cooking, or lab readings, you’re in temperature territory and °C is the right mental model.

How To Say It And Write It Without Awkward Moments

In speech, “degrees Celsius” is clear, and “degrees C” is common shorthand. “Centigrade” still shows up in conversation, and it usually lands fine. In writing, “Celsius” is the safer pick since it lines up with current unit standards.

For the symbol, use the degree sign and an uppercase C: 23 °C. Skip “°c” and skip “C°”. If you need the word form, write “23 degrees Celsius” in running text.

Spacing And Plurals

Write a space between the number and the symbol: 23 °C, not 23°C. Keep the symbol the same in singular and plural. You don’t add an “s” to °C.

When you write the words, the plural follows normal English: “1 degree Celsius” and “2 degrees Celsius.” In notes where you list a lot of readings, sticking to the symbol saves space and reduces typos.

When you want the form that matches science style guides, use “degree Celsius” and the symbol °C. The naming choice was formalized in metrology decisions; see the BIPM record on adoption of “degree Celsius” (CIPM, 1948).

On top of the name, there’s a small formatting rule that teachers and editors love: put a space between the number and °C. The NIST rules for writing unit symbols like °C spell this out in plain terms.

Negative Temperatures And Decimal Points

Negative values are common in °C, so a clean minus sign matters: −5 °C. If you type a hyphen, it’s still readable, yet a true minus sign looks cleaner in print.

For decimals, choose a consistent style: 36.6 °C or 36.6 degrees Celsius. Don’t swap between 36.6 and 36.60 unless the extra digit carries meaning in your measurement.

Converting Celsius And Fahrenheit Without Slipups

You don’t need conversions to answer the naming question, yet conversions pop up any time you read a recipe, a US news report, or a science worksheet. The formulas are simple, and the main traps are order of operations and rushed rounding.

Celsius To Fahrenheit

Multiply the Celsius value by 9, divide by 5, then add 32.

• Formula: °F = (°C × 9 ÷ 5) + 32
• Quick check: 0 °C becomes 32 °F

Fahrenheit To Celsius

Subtract 32, then multiply by 5 and divide by 9.

• Formula: °C = (°F − 32) × 5 ÷ 9
• Quick check: 212 °F becomes 100 °C

Mental Math Shortcuts That Stay Honest

If you just need a ballpark, these tricks work well:

• From °C to °F: double °C and add 30 to get a fast estimate near room temperature.
• From °F to °C: subtract 30 and halve to get a fast estimate near room temperature.

These shortcuts drift as you move far from room temperature. Use the full formula for freezing weather, ovens, or lab data where a few degrees matter.

Celsius Benchmarks You’ll See Often

When you learn a few anchor points, °C starts feeling intuitive. The table below lists everyday and science-adjacent reference points that pop up in school, health forms, cooking, and weather.

Common Reference Points In Degrees Celsius

Reference Point	°C	Notes
Water freezing point	0	Ice and liquid water can coexist
Cool room	18–20	Light sweater range for many people
Typical room	20–22	Common indoor target
Warm day outdoors	25–30	Short sleeves in many places
Hot day outdoors	32–38	Heat risk rises as humidity climbs
Body temperature (oral)	37	Often given as a mid-point
Fever threshold used in many clinics	38	Rules vary by country and method
Water simmering	85–96	Small bubbles, not a rolling boil
Water boiling point	100	At sea level pressure
Low oven	150–160	Slow baking, drying
Moderate oven	175–190	Many cakes and casseroles
Hot oven	200–230	Roasting, crisping

Common Mix-Ups And Clean Fixes

This topic feels simple until a small formatting slip costs you points on an assignment or makes a label look odd. Here are the mistakes that show up most.

Writing C When You Mean °C

A plain “C” can look like a variable name. Use the degree sign for temperature: 10 °C, not 10 C. If you’re typing on a phone, set up a text shortcut for “°C” so you don’t skip it.

Swapping The Symbol Order

Put the degree sign first, then the C: °C. “C°” looks like a typo and can confuse readers who skim.

Mixing Temperature With Temperature Change

In many classes, a temperature difference can be written in K or in °C with the same number. Still, be clear in your wording: “rose by 5 °C” is different from “is 5 °C.” The first is a change, the second is a reading.

Using Centigrade In Formal Writing

Most teachers won’t mark “centigrade” wrong in a casual answer. In lab reports, engineering work, and edited writing, “Celsius” is the safe label. When someone asks “are centigrade and celsius the same?” you can say yes, then add that “Celsius” is the name you’ll see in standards and unit rules.

Quick Checklist For Notes, Labels, And Homework

• Use “Celsius” in writing unless a teacher or manual asks for “centigrade.”
• Write the symbol as “°C” with a space after the number: 21 °C.
• Keep the C uppercase.
• Use a minus sign for cold readings: −7 °C.
• Use the full formula for conversions when accuracy matters.
• Watch for surveying context where “centigrade” may mean gradians.

If you’re unsure, write °C and spell out Celsius at the start.

One Last Thing To Store In Your Head

If you see °C, you’re looking at the Celsius temperature scale, no matter what the surrounding text calls it. The word “centigrade” is mostly a legacy label for the same scale.

So the next time that question pops up, you can answer it in a sentence, write the unit in the right format, and move on with your day.