American travelers, this one is for you! This piece explains how to convert Celsius to Fahrenheit quickly when you’re traveling abroad. As a bonus, we’ve even thrown in some quick ways to convert kilometers to miles. Enjoy!

Raise your hand if you’ve been in this situation: You’re on vacation in another country. You wake up in your hotel after a restful sleep, and you start thinking about how you’d like to spend your day. Will you hit the beach, head out for a hike, or visit a museum?

If  you’re like me, your choice might depend on the weather. I mean, nobody wants to go to the beach in the rain or hike on a scorcher of a day, right? So, you turn on the TV or open your phone’s weather app to check the forecast and…hmmm…that can’t be right. It’s only 27 degrees?!?

Right about then, it probably dawns on you that you’re not dealing with freezing temperatures. Instead, you’re dealing with that pesky metric system.

The Metric System

Why oh, why oh, why oh would anybody ever use the darn metric system?

Well, according to Wikipedia, the metric system is “an internationally adopted decimal system of measurement.” The key phrase here is “internationally adopted.” As in, basically every country in the world uses it.

But not us! Here in America, we’re stubborn. We do things our own way, and in this shining city on a hill, we’re still holding out hope that the old way of measuring weight, distance, and temperature will prevail!

Unfortunately for Americans, that battle has been lost. The international community has spoken, and they all agree that the metric system is the way to go. This also means we’re out of sync with the rest of the world when it comes to measurements.

While we still think in terms of degrees Fahrenheit, feet, inches, pounds, and miles, people living in countries that use the metric system don’t. Instead, they use degrees Celsius, meters, centimeters, kilograms, and kilometers.

This might not seem like a big deal, but – when you’re traveling – being unable to understand the forecast, the speed limit, or the distance to your destination can get old pretty fast. Not to mention, it can also be super embarrassing if it comes up in a conversation with the locals. I mean, you don’t want to be visiting Dublin and be unable to hold a conversation, do you? The weather is the universal topic of small talk, after all.

Luckily, we’ve put together this handy guide for converting degrees Celsius to Fahrenheit and kilometers to miles.

Quick and Dirty Celsius to Fahrenheit Conversions

Trust me, when our family is traveling to the Loire Valley in France, being the dumb Americans who can’t gauge the temperature kind of sucks. Thankfully, that no longer has to be you.

If you don’t have your phone, a calculator, or a computer handy, use this quick formula to estimate the Celsius to Fahrenheit conversion:

Celsius Temperature x 2 + 30 = Approximate Fahrenheit Temperature

Pretty easy, right?

For example, if you’re checking the weather and it says 27 degrees Celsius, that’s 27 x 2 = 54 + 30 = 84. So, 27 degrees Celsius is approximately 84 degrees Fahrenheit. In other words, it’s a pretty warm day.

Keep in mind, this is only an estimate. As the temperature grows warmer, the formula becomes less accurate. But hey, you’re not reporting the weather; you’re just trying to interpret the forecast and not feel like an idiot. So, for your purposes, this formula will work just fine.

Celsius to Fahrenheit: The Real Deal

If you want to be precise, the actual formula for converting Celsius to Fahrenheit is this:

Celsius Temperature x 1.8 + 32 = Fahrenheit Temperature

So, if we go back to our 27 degrees Celsius example, we get:

27 x 1.8 = 48.6 + 32 = 81

Thus, 27 degrees Celsius is actually equal to 81 degrees Fahrenheit. You can see how this is a bit off from our estimate of 84 degrees, but it’s in the general ballpark.

For reference, the following table shows a range of Celsius temperatures and their Fahrenheit counterparts. So, the next time you’re looking for things to do in London, you can use this handy little chart to decide if the weather will permit it. We’ve started the table at -40 °C and went up to 40 °C – let’s hope you aren’t vacationing in any temperatures more extreme than those!

Celsius to Fahrenheit Conversion Table (Rounded to Whole Degrees)

Celsius (°C)Fahrenheit (°F)
-40 °C-40 °F
-30 °C-22 °F
-20 °C-4 °F
-10 °C14 °F
-9 °C16 °F
-8 °C18 °F
-7 °C19 °F
-6 °C21 °F
-5 °C23 °F
-4 °C25 °F
-3 °C27 °F
-2 °C28 °F
-1 °C30 °F
0 °C32 °F
1 °C34 °F
2 °C36 °F
3 °C37 °F
4 °C39 °F
5 °C41 °F
6 °C43 °F
7 °C45 °F
8 °C46 °F
9 °C48 °F
10 °C50 °F
20 °C68 °F
30 °C86 °F
40 °C104 °F

Kilometers to Miles on the Fly

Now that you understand the Celsius to Fahrenheit conversion, let’s move on to converting distance and speed.

Tired of being the silly American traveler who can't convert Celcius to Fahrenheit? Here are some easy tips to make metric conversions in a snap!

Just like converting temperature, not understanding speeds and distance can be a problem for Americans when traveling.

Let me say this: The speed limit on Canadian highways is definitely not 100 miles per hour (mph). 100 kilometers (km) per hour is a whole different thing, and works out to be about 62 mph. Mixing that up means you’ll likely have problems with law enforcement. I don’t know about you, but I can’t think of a faster way to put a damper on a vacation than by getting a ticket. (Extra points if you caught that pun…)

Even if you’re not driving, it’s useful to understand just how far a km is. If someone tells you a destination is 5 km away, you need to be able to assign meaning to that.

Here are a couple of quick tricks for quickly converting km to miles:

5 miles = 8 km

For example, 50 miles = 80 km. So, if you see a speed limit sign that says 100 km per hour, it means about 60 mph.

How do we get those numbers? If you’re converting km to miles, you want to divide the km by 8 and multiply by 5. So, 100/8 = approximately 12, multiplied by 5 = 60.

If you’re going from miles to km, you’ll need to divide by 5 and multiply by 8. It’s not precise, but it’s close enough.

Here’s another rough estimate:

Km divided by five and then multiplied by 3 = Approximate miles

For example, 75 km/5 = 15 x 3 = 45 miles

If you want to convert miles to km, you simply reverse it. Divide the miles by 3 and multiply by 5 to get your answer.

Again, this isn’t precise, but it’s fine for a quick estimate.

Km to Miles: The Real Deal

If you wanna get nitpicky about it, 1 km is actually equal to 0.621 miles. So, to convert km to miles, you just need to multiply it by 0.621. Now, if you can do that in your head on the fly, you’re a lot better at math than I am!

On the other hand, if you’re not a superhuman math wiz, here’s a table with (almost) exact km to miles conversions that you can use for reference.

Km to Miles Conversion (Rounded to One Decimal Place)


Metric Conversions for Travel: Final Thoughts

So, there you have it – one quick way to convert Celsius to Fahrenheit and two easy ways to convert kilometers to miles. Just in case you need to be a bit more exact, you’ve also got the real formulas and corresponding reference tables.

Most importantly, the next time you’re in Switzerland (or any other part of the world), you don’t have to worry about being that clueless American who can’t navigate the darn metric system. You’re welcome 😉

Do you have a fast way to convert Celsius to Fahrenheit we didn’t cover? Let us know in the comments below! Tired of being the silly American traveler who can't convert Celcius to Fahrenheit? Here are some easy tips to make metric conversions in a snap!