enjoy — europe.com
travel with John Bermont

The original do-it-yourself travel guide to Europe ℠

Europe's Metric System

Travel with Grams, Meters, Liters, and Centigrade

This explains the metric system as used in Europe and how to convert USA to metric units.

Chapter 27 of

HOW TO EUROPE: The Complete Travelers Handbook John Bermont — Chef du Site

The entire book is published free on-line by author and photographer John Bermont, yours truly, with help from my daughter Stephanie. Copyright statement. Home page at enjoy-europe. Update 26 February 2015.

Carpe diem. Vivere bene! Gratia Deo.

Brought to You by Euro-Shoppe is your go-to Internet source for travel supplies. Your Go-To Travel Store Luggage, 220 v electric plug adapters, dual voltage hair blowers, clothes, guide books, dictionaries, cameras.

You'll have to go metric in a hurry.

Weights and measures in Europe are drastically different than those we know in the USA. Every country uses the metric system, with only a few exceptions and only in Britain. Even that is different in peculiar ways.



First, let's take a short refresher course on ordinary American weights and measures. The American system is derived from the system historically used in Britain. Because it is "derived from" you may correctly infer that they are not identical.

The smallest unit of weight in everyday use is the Avoirdupois ounce. We call it the ounce. Next up is the pound, 16 ounces. Then we jump to the ton, 2,000 pounds. Internationally speaking, the American ton is known as the short ton. A hundredweight, 100 pounds, is also used in commerce.

American liquid measurements normally start with the fluid ounce, not to be confused with the ounce used in weight measurement. Increasing quantities are the pint of 16 fluid ounces, the quart of two pints, and the gallon of four quarts. A pint of water weighs about one pound. Cooks also use the cup measurement of 8 ounces.

Length measurement starts with the inch, about the length of the last digit of your index finger. Then 12 inches make a foot, three feet make a yard, and 5,280 feet make a mile.


Troy weights, named after the French city Troyes, are used for precious metals. The troy ounce is about 10% heavier than an avoirdupois ounce. But a troy pound is 18% lighter than an avoirdupois pound. The reason for this apparent discrepancy is that there are 16 ounces in an avoirdupois pound and only 12 ounces in a troy pound. Unless you are a jeweler you won't often see troy weights.


The first stop for Americans is often England. There is where you'll find your first confusion. The British formerly used the same names for weights and measures that we do but this is now generally illegal. A British green grocer was arrested and tried for selling bananas by the pound. He was convicted of this heinous crime and summarily punished. Britain is a member of the European Union which has decreed metric for all members. Britain has joined the metric club with limited exceptions to the old system.

Road signage is still in miles and ale is still served by the pint in British pubs, indefinitely. A British mile is the same distance as an American mile but a British pint is an imperial pint, 20% larger than an American pint. A British pint has 20 imperial ounces so you would expect that it would be 25% larger than an American pint of 16 ounces. But, the imperial fluid ounce is smaller than an American fluid ounce. The correct answer is that an imperial pint is 20% more than an American pint. Now you can find a trivia game and win the weights and measures category.

Oops, the game is not over. When you buy your brew in a store it has to be in a metric container. An imperial pint is 568.26 milliliters. If the pub pint of ale ever gets outlawed you would have to order a five-sixty-eight-point-twenty-six. I guess the bar keeper will know you've had too many when you can't get all of that out of your mouth.

A unique British unit of weight is the stone. People weigh themselves in stone, or at least they did before the UK went metric. One stone is 14 pounds.


Metrics in America

Most Americans have heard that the United States is converting to the metric system. Some busy-bodies are not content with the simple units of measure that we grew up with and for various reasons they have advocated that the USA convert to the metric system. Their rationale is that most of the rest of the world has already gone metric. I say "So what?" In fact, metric was made legal in the USA way back in 1866 but never sold a napkin. If it ain't broke why fix it? Pounds, yards, and gallons worked for daddy so why change it?

In recent years the metric advocates have succeeded in getting Congress to require metric units on many products. For the past 10 years or so all product labels now have the metric equivalent of the weight, length, or volume in parenthesis next to the good old American way of measuring things. For example, here I have a 20 ounce (567 gram) can of sugar and a box of hand wipes 8 inches x 12.5 inches (203.2 millimeters x 317.5 millimeters). Having those metric units on the labels is just so darn practical — not.


Before you start accusing me of having metricphobia please be aware that I have been using both American and metric units from university days throughout my career, and doing it comfortably. I am a chemical engineer. In doing design calculations for chemical processes I must use data from laboratories. Chemists use metric units for EVERYTHING in the laboratory. Chemical engineers use all that metric lab data and produce results in American units for darn near EVERYTHING. Therefore, I have been converting grams-per-liter to pounds-per-gallon and doing many similar calculatons for decades, since long before electronic calculators and computers came along and made the task a bit easier. There is a gradual change taking place in this niche of technology. The change is primarily driven by American multi-national companies which want to use global standards for business purposes, not because they love metric meters and grams and such. That's good. Let the free market decide, not some political hack or government clod.

On a more personal note, for many years I was the only person on my block who owned a set of metric wrenches. When I was young I liked to do my own auto engine work, the minor stuff. My first three cars were a Volkswagen Beetle (affectionately known as the "Bug" or the "V-Dub"), a Karmann Ghia convertible, and a Porsche 911S. They were all made in Deutschland (Germany) and were all 100% metric.

Enough of the personal stuff. Let's get into the meat of the metric system.

What Is the Metric System?

The metric system is a decimal system of weights and measures in which the gram is the unit of weight, the meter is the unit of length, and the liter is the unit of volume.

These units are conveniently related:

1,000 kilograms is a metric ton, also known as a long ton. It weighs 2,200 pounds, 200 pounds more than an American ton.

Amounts greater or smaller than grams, meters, and liters are expressed by adding prefixes derived from Greek and Latin words for ten, hundred, and thousand. Thus you have:

Units Prefix Example
1000 kilo- one kilogram = 1000 grams
100 hecto- one hectoliter = 100 liters
10 deca- one decameter = 10 meters
0.1 deci- one decimeter = 1/10 meter
0.01 centi- one centiliter = 1/100 liter
0.001 milli- one milligram = 1/1000 gram

Additional prefixes are available for millions and billions but you won't see those on the store shelves, well, except in computer stores where everything is mega-, giga-, and tera- these days. You already know that.

The centi- prefix is one of the most common you will see and always means 1/100th of whatever. This is easy to remember because the American cent is 1/100th of a dollar. Cent shows up in many other places as well, such as century, centipede, centurion, centigrade, and cent, the French word for 100.


We seldom write out pounds and gallons but usually use lbs. and gals. Europeans do the same with metric units. Here are some common abbrs.:

  Weight Volume Length
kilo- kg kl km
hecto- hg hl hm
deka- dag dal dam
Basic Unit g l m
deci- dg dl dm
centi- cg cl cm
milli- mg ml mm

Using Metric

The conversion factors for the basic units into common American units are:

Basic Unit Conversion Factors
One gram equals 0.0352739 ounces
One liter equals 1.056710 quarts
One meter equals 3.280833 feet

Six place conversion factors are of little use to the traveler. You want to be able to relate quantities in the European units to American units in a flash. It's like learning a foreign language, but far easier because you don't need to learn any grammar.

Think in metric units, approximately. For example, consider the following conversions and the round off approximations in the next column:

Rounded Off Conversion Factors
Exact Conversion Factor Round Off
1 ounce 28.349527 grams 1 oz 30 g
1 kilogram 2.204619 pounds 1 kg 2 lb
100 grams 3.52739 ounces 100 g 1/4 lb
33 centiliters 11.15884 fluid ounces 33 cl 11 fl oz
1 liter 1.06573 quart 1 l 1 qt or ¼ gal
1 gallon 3.785332 liters 1 gal 4 l
1 inch 2.538998 centimeters 1 in 2½ cm
1 foot 30.48006 centimeters 1 ft 30 cm
1 meter 1.093611 yards 1 m 1 yd
1 mile 1.60931 kilometers 1 mi 1½ km

These approximations are close enough to get you through the day.

Familiar derivations of American units are also much different. For instance, automobile engine sizes in the USA are normally rated by cubic inch displacement. Europeans use liters. One liter equals 61 cubic inches. Our horsepower is equal to about ¾ of their kilowatt (KW) so if you see a car with a 100 KW engine that is about 134 HP to you. Americans use kilowatts to measure electricity, not automobile horsepower. For the tires, 30 psi equals approximately 2 atmospheres, 2 bars, and/or 2 kg/cm2. For you sailors, wind speed is measured in meters per second. Ten m/s equals 19 knots. On land, 10 m/s equals 22 mph.

Oops, one last conversion factor – 35 liters per bushel.

Metric Odds and Ends

The touted benefit of the metric system is that units are converted to higher or lower units of measure by factors of ten only. On the other hand, the American system has twelve inches to the foot, three feet to the yard, and many other divisions and multiples of units. One small absurdity of the metric system is that nobody uses many of the named units, e.g. dekagrams and decigrams. Hectograms are rarely used. I've only seen them in produce and fish markets in Italy.

Another problem with the metric system is the size of the basic unit of weight, the gram. The only place where it is at all meaningful is in the post office for weighing mail, but even there an ounce makes more sense than 28 grams. In Europe the maximum weight of an envelope for the minimum price is only 20 grams, about 30% less than in the USA. If you think that our postage rates are atrocious you will positively choke when you see what it costs to send a letter across the city of Paris or a postcard home. For more about the legacy postal system see Sending Snail Mail to & from Europe.

Most products in Europe are sold by the kilogram, kg. A kilogram is 1,000 grams and equal to about 2 pounds. But in Holland the word pond is used colloquially to mean 500 grams, slightly more than an American pound. The Germans have their Pfund and the French their livre to parallel the Dutch. There is obviously a practical need for a unit which is about equal to the American pound but the metric system has nothing to offer. The Dutch also use the word ons for 100 grams. However the translation of ons is ounce and that is only 28 grams, not 100.

I don't know if McDonald's will have to rename their quarter pounder. In metric it would be a 113.5 grammer.

International System of Units, SI

You may see the term SI in documents and scientific papers. This is the official name for the metric system. The SI abbreviation is derived from the French name, Systeme International.



America uses the Fahrenheit temperature scale. On this scale water freezes at 32oF and boils at 212oF.


The Centigrade temperature scale is used in Europe. It is also called the Celsius scale after its Swedish inventor. In Centigrade water freezes at 0oC and it boils at 100oC. That is a 100 degree span, thus our old friend centi- again.

Fahrenheit and Celsius temperatures can be converted back and forth with a simple algebraic expression. To convert Celsius to Fahrenheit multiply oC by 1.8 and add 32. To convert Fahrenheit to Celsius subtract 32 from oF and then divide by 1.8.

I know that is too much math for a few of you (I teach algebra so I know whereof I speak) and I seldom do it myself. Instead, keep some benchmarks in mind. Easy points to remember are:

Centigrade/Fahrenheit Conversion Table
oC -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 100
oF -4 5 14 23 32 41 50 59 68 77 86 95 104 212

You can see that for every span of five Centigrade degrees there is a span of nine Fahrenheit degrees, exact.

Key Temperatures

A good beach day would be 25oC. Normal body temperature of 98.6oF is equal to 37oC. The only temperature at which Centigrade and Fahrenheit are the same is 40o below zero. You won't find me in town when that happens.


When the metric system was introduced it also applied to time in France. After the Revolutionaries chopped off the heads of Louis and the Royals they moved forward. They decided to get rid of the old 60 seconds per minute, 60 minutes per hour, 24 hours per day, 7 days per week, and circa 52 weeks per year. It was all merde in their view because the Royals used it and made the prols use it.

The Revolutionaries went to a decimal time system. This featured 100 seconds per minute, 100 minutes per hour, 10 hours per day, and 10 days in a week.

Not all change is good. Napoleon Bonaparte used his emperor status and got that idiocy unhinged. France went back to the good old fashioned clock and calendar. I guess that the Revolutionaries would have had a better case if they had redefined the second as 13.6% less. Then the annual reckening would have been off by only 5 days but it would even out in the next year.


I welcome questions and comments. If you have any concerns about your trip to Europe that have not been covered well enough on my web site please do not hesitate to write and ask. When you write please include relevant details.

I do not open attachments. Please include all of your data in the body of your email. I will reply in a day or two.

Do not forget to smell the hyacinths. Scroll through the Table of Contents of How To Europe: The Complete Travelers Handbook and read all 30 chapters, FREE on line. Good deal! You'll probably find the answers you seek, and some you didn't know you needed.

My email address is johnbermont@enjoy-europe.com.

Have a good trip!


Internet edition
© 2001-2015 James J. Broad
All rights reserved. Tous droits réservés.
This is copyrighted material.
Do not reproduce, copy, plagiarize, store, modify, extract, transmit, or purloin any part of this publication in any nation in any form or by any means or for any purpose whatsoever without permission in writing.


You may print one copy of this chapter for your personal use.


If you want to copy any of this material to any blog, forum, web site, book, article, speech, term paper, or any other media please ask first. Copyright violators and plagiarists are tracked down. Note that plagiarism includes paraphrasing text, copying ideas, and imitating images unless you give credit to the originator. Imitation, as the old saying goes, may be the highest form of flattery, but it is also theft and is usually compounded by the lies of the perpetrtor claiming originality. Everything on this page is original. Please respect my property.
For permissions contact: johnbermont@enjoy-europe.com.


You may link the URL http://www.enjoy-europe.com/hte/chap27/metric.htm freely. Please do. When you link please send the URL for your linking page and a crosslink will be installed in one of the categories of the TRAVELERS YELLOW PAGES to your site if it has significant content for travelers in Europe.


Bon voyage on site, and all over Europe!