When it comes to Fahrenheit vs. Celsius, the world is in agreement—mostly. Here's why the United States is still stuck on Fahrenheit.
Here’s Why the U.S. Uses Fahrenheit vs. Celsius
Updated on May 15, 2025
It’s no secret that Americans have an independence streak. We don’t use the metric system. We insist on writing dates with the month before the day—something virtually no other country does. And we tip almost everyone we interact with (at least it feels that way!). To top it all off, we use a different temperature system than most of the world, relying on a Fahrenheit vs. Celsius scale.
You’d think that temperature would be universal, like the four directions. But here’s an interesting fact: There are not just two but three different temperature systems. The third is Kelvin, which (luckily) only scientists use to chart temperatures that we don’t encounter in daily life, like absolute zero or the temperature of stars.
Still, that leaves us with two different systems—and a lot of confusion. How did we end up so divided? And which came first: Fahrenheit or Celsius? Read on as we dive into the history, discover the differences and explain why America is in the minority with its use of Fahrenheit.
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Fahrenheit vs. Celsius: What’s the difference?
The main difference between Fahrenheit and Celsius lies in each temperature system’s scale size, with the boiling and freezing points of water being a key indicator.
Celsius scale
- Water freezes: Zero degrees
- Water boils: 100 degrees
Fahrenheit scale
- Water freezes: 32 degrees
- Water boils: 212 degrees
According to Britannica, the Fahrenheit scale is “divided into 180 equal parts” between the two intervals. The Celsius scale, on the other hand, has 100 degrees between the freezing and boiling points.
Keep in mind that the scale for both temperature systems extends beyond the defined boiling and freezing points for water. After all, the temperature in Antarctica goes down to a chilly minus 58 degrees Fahrenheit (minus 50 degrees Celsius) in winter, and the sun’s surface scorches at 10,000 degrees Fahrenheit (5,500 degrees Celsius).
How do these terms affect our view of the temperature?
Specifying Fahrenheit vs. Celsius is important, especially in a global context. Think about it: If someone online told you that it was 40 degrees outside, would you imagine them in shorts or a sweater?
For most people around the world, a 40-degree day is crazy hot. Add 5 more degrees Celsius to it, and modern air-conditioning systems would stop working. But in the United States, a 40-degree day is fairly cool. Without context, hearing people complain about sweating in 40-degree weather can be perplexing, making the difference—or rather, the math—between Fahrenheit and Celsius all the more important. (We’ll save you the steps: 40 degrees Celsius is 104 degrees Fahrenheit!)
When were the Fahrenheit and Celsius scales invented?
Believe it or not, there was a time (although very brief) when using Fahrenheit made perfect sense because it was the only way of measuring temperature. And here’s how it was invented:
The invention of the Fahrenheit scale
In the early 1700s, thermometers were rudimentary, few and far between, and imprecise. The man who invented the first modern thermometer has a name that might ring a bell: Daniel Gabriel Fahrenheit. In 1714, this Polish-born Dutch physicist became the first person to make two thermometers that showed the same reading.
Ten years later, he developed a scale bearing his name—Fahrenheit—to measure temperature. He set zero degrees as the lowest temperature he could get a mixture of salt and water to reach. He approximated the temperature of the human body as 96 degrees for another fixed point.
The invention of the Celsius scale
Only 18 years after Fahrenheit’s breakthrough, a scientist named Anders Celsius developed a second system of temperature measurement—a much more intuitive one at that. This one, of course, had an even 100-degree difference between the freezing and boiling points of water.
It would have been a serious bummer to be Fahrenheit … if countries like the United States didn’t continue to use his system to this day.
Does the U.S. use Fahrenheit or Celsius?
The United States uses Fahrenheit to measure temperature. And it all makes sense—once you look at the history behind it.
During the 18 years that Fahrenheit was the lone temperature-scale player, the system gained substantial footing. The British Royal Society had adopted it, and England spread it to its colonies, including the United States and Australia.
But Celsius’s affinity with the nascent metric system could not be ignored. They were both based on multiples of 10, making things a lot easier. France’s government spearheaded the adoption of the metric system and Celsius with it. This intuitive system spread to much of the world. But at the same time, the English-speaking world continued to hang on to Fahrenheit (at least for the time being).
In the 1960s, the United Kingdom began officially switching over to the metric system so that it would be in step with the rest of Europe. America, however, made no such switch.
But here’s an interesting piece of U.S. trivia: Lawmakers took a crack at introducing the metric system in 1975 with Congress’ Metric Conversion Act. This act made adopting the metric system voluntary. And to no one’s surprise, people had no desire to voluntarily upend the systems of measurement—quirky and unwieldy as they may be—that they were familiar with and operated with.
What countries use Fahrenheit?
Throughout history, countries around the world have had to pick a side in the Fahrenheit vs. Celsius debate. Other than the U.S., there are a few nations that hold on to the Fahrenheit system.
You’ll still be able to relish official 70-degree weather in the following countries:
- Bahamas
- The Cayman Islands
- Palau
- The Federated States of Micronesia
- The Marshall Islands
- Liberia
Some other nations use both temperature systems, including Belize, the British Virgin Islands and Bermuda.
If you’re traveling to a country that measures temperature differently from yours, it’s helpful to know the conversion rates for Fahrenheit to Celsius and Celsius to Fahrenheit. It’ll require you to put on your math hat (which many of us prefer leaving at home when headed for a vacation), though there are apps that’ll do the work for you.
FAQs
How do you convert Fahrenheit to Celsius?
Temperature conversion from Celsius to Fahrenheit, and vice versa, can leave the best of us scratching our heads. Here’s a quick formula, courtesy of the National Institute of Standards and Technology, that will simplify the process, even if you’re not a math genius.
To convert from Fahrenheit to Celsius:
- Subtract 32.
- Multiply by 5.
- Divide by 9.
To convert from Celsius to Fahrenheit:
- Multiply by 1.8.
- Add 32.
Say you need to convert 40 degrees Celsius to Fahrenheit. Here’s the order of math you need to perform: (40 × 1.8) + 32, which translates to 72 + 32 = 104 degrees Fahrenheit.
Which is colder, Celcius or Fahrenheit?
Celsius and Fahrenheit are just two different scales, so one isn’t inherently “colder.” But numerically, zero degrees Fahrenheit is colder than zero degrees Celsius. In fact, zero degrees Celsius equals 32 degrees Fahrenheit, which is the freezing point of water. So a negative number in Celsius is much colder than the same number in Fahrenheit. Minus 10 degrees Celsius equals 14 degrees Fahrenheit, but minus 10 degrees Fahrenheit is minus 23 degrees Celsius.
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Sources:
- Britannica: “Fahrenheit temperature scale”
- Britannica: “Daniel Gabriel Fahrenheit”
- Britannica: “Celsius temperature scale”
- United States Antarctic Program: “About the continent”
- NASA: “Temperatures across our Solar System—Sun”
- Thought Co: “The History of the Thermometer”
- Vox: “Why Americans still use Fahrenheit long after everyone else switched to Celsius”
- How Stuff Works: “Why Does the U.S. Use Fahrenheit Instead of Celsius?”
