Metric Conversion Guide for Travelers

Metric ruler

Overseas travel from the United States requires an understanding of the metric system for weights, measures and volume. Gas in the United Kingdom and the European Union is sold by the liter, not the gallon. In addition, distance is measured in kilometers rather than miles, as is speed. For travelers planning on renting a vehicle, you'll need to understand the difference in order to budget appropriately. With a few tricks, you can convert one system to another on the fly. This quick metric conversion guide can help you translate the distances from standard to metric units. If you need help downloading the conversion guide, check out these helpful tips.

Shopping and the Metric System

Remember when stepping into a grocery store in the U.K. you will be purchasing volumes in grams, kilograms, liters and milliliters. Milk, for example, is rarely sold as a gallon in the cold section. Instead it's often boxed by the liter and must only be refrigerated after opening. In the produce section, you will find fresh fruits and vegetables along with a weight system. You weigh your produce, enter the numbered code next to the price and it will print out a tag that can be rung at the register. The prices may seem expensive, but remember, particularly in the United Kingdom, you are dealing with expensive imports and different weight systems.


Whether purchasing milk at the grocery store or petrol (gas) at the filling station (gas station), you'll be dealing in liters, not gallons or half-gallons. Gas prices in the U.K. and European Union are significantly higher than they are in the United States, particularly when you are dealing in liters. Be sure to take the following measurements into consideration:

  • One liter is equal to about one-quarter of a gallon or a little over one quart.
  • Milk is often sold as a boxed liter, fresh milk may be sold in a glass-bottled liter


Converting kilograms to pounds is a little trickier to calculate in your head. Luckily these weights aren't often used in day-to-day travels. If you are shopping for produce, it's good to keep a couple of basic weights in your mind, so that you know what you're buying. For example, one kilogram is just over two pounds, and one pound is just under half a kilogram. The conversions below are very rough, but help in a pinch:

  • Multiply one kilogram by 2.2 to translate into pounds
  • Divide one pound by 2.2 to translate into kilograms


Distances in the U.K. and Europe are measured by kilometers and meters. For example, 10 kilometers is roughly six point two miles. One kilometer is about three-quarters of a mile. It can be frustrating at first, but with time and practice, you'll be able to convert distances in a snap. Just remember:

  • Meters are roughly the same as yards
  • One inch is equal to 2.5 centimeters
  • A kilometer is roughly three-quarters of a mile
  • One foot is about 30 centimeters


Fahrenheit and Celsius are two ways of measuring temperature. Fahrenheit uses 32 degrees as a base for the freezing point of water, while Celsius uses 0. Across much of Europe and the U.K. daily weather forecasts will be given in Celsius. You will need to translate this so you know how to dress appropriately. Simple ways to remember the conversion include:

  • To convert from Celsius to Fahrenheit, double the number, then add 32. So, to find the Fahrenheit equivalent of 8 degrees Celsius, your mental formula would look something like this: 8C x 2 = 16C + 32 = 48F
  • To convert from Fahrenheit to Celsius, subtract 32, then half the number. For e xample: 54F - 32 = 22 / 2 = 11C

This isn't an exact conversion, but will get you close enough to the real temperature that you'll be able to know what to wear.

Pay Attention To The Differences

It's important to take note of the differences between metric and imperial measurements when you travel, not only to budget accordingly, but also to avoid misunderstandings. Carry a chart in your wallet or bag for quick conversions and don't be afraid to ask the locals for help.

Metric Conversion Guide for Travelers