Rick Steves' Not-Perfectly-Accurate But Simple Little Trick To Help American Tourists Think In Celsius

"What's 25 degrees Celsius in Fahrenheit? Is that warm, or should I bring a jacket?" If you've ever had to check the weather while traveling or living abroad — or even just taken your temperature during a fever — you'll have likely run into some numbers that require quick conversions. To much of the world, Celsius is the go-to temperature scale — metric-based, internationally standardized, and some might even say logical. Yet in the United States, Fahrenheit still reigns: Americans continue to measure heatwaves and cold snaps using a scale that, well, hardly anyone else uses. But when you're trying not to come off like a clueless tourist that drives locals up a wall, not even a calculator will help if you don't know what exactly to calculate. What's the best way to convert Celsius to Fahrenheit for an American brain, and is there a way to remember it quickly and effectively? 

With all the best travel tips we've learned from Rick Steves, the travel expert has yet another trick up his sleeve: a simple way to convert Celsius to Fahrenheit (and vice-versa) so you don't have to pull out a calculator or conversion app every time you check the temperature on your vacation. Yes, it involves math, but it's a straightforward equation that's usually pretty accurate — or at least in close range. Once you get the hang of it, you'll be, as Rick Steves says, a traveler, not a tourist.

According to Rick Steves' blog, the basic way to convert Celsius to Fahrenheit is to double the Celsius number and add 30. Zero degrees Celsius is 32 degrees Fahrenheit, the scientific freezing point in both systems, and the boiling point is 100 degrees Celsius and 212 degrees Fahrenheit (when the temperature is -40 degrees, it is the same in both Celsius and Fahrenheit). While technically the equation of conversion is F = 1.8C+32, it's much easier to round up to 2 and round down to 30 when doing quick math. The results will be fractionally off, but as long as you're not doing rocket science with those numbers, you'll be within an accurate range. 

For example, if it's 10 degrees Celsius, you'd double it to get 20, then add 30 to get 50 degrees Fahrenheit (it will feel the same either way — grab a jacket!) If you want to do the reverse and convert Fahrenheit to Celsius, take the Fahrenheit number, subtract 30, and divide by 2. For a thermometer that reads 75 degrees Fahrenheit, subtract 30 to get 45, then divide 45 by 2. It's now roughly 23 degrees Celsius. 

Steves adds that a helpful way to remember this is that 28° C = 82° F, which is a balmy summer day. This numerical palindrome is an easy way to remember a basic temperature conversion, so you won't be totally clueless. On a Rick Steves blog forum, travelers agreed with the equation trick, with mnannie from Northern Minnesota quipping, "I just double, and add 30. If it's before 0, we are usually at home." After all, even Steves probably agrees that "cold is cold!"