Category Archives: Metric Cooking

The “Preferred” Measurement System of the US

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By The Metric Maven

Bulldog Edition

The object to the left is an everyday thing, but it is making a clear statement about the designer’s measurement preference. It may not be apparent what the measurement preference is to you. It might not have been to me had I not read The Design of Everyday Things by Donald A Norman (suggested to me by Sven). The design of even the simplest of objects is done in a manner that provides information on how the designer intends them to be used. A person will unconsciously take an intended design clue, and use an object as intended. Knives are provided with handles, and one doesn’t stop to think which is the best end to hold in one’s hand after early experience and instruction in childhood. Norman cites research which argues there are at least 30,000 everyday things around us, and decreases the number to 20,000 to state: “Suppose each everyday thing takes only one minute to learn; learning 20,000 of them occupies 20,000 minutes —333 hours  about 8 forty hour work weeks.” We have a considerable amount of time invested in learning about our everyday things. When we encounter a can opener, or a scissors, or a potato peeler, we generally know exactly what to expect, how to hold it, and how to use it. One way that a designed object signals how it should be used, is to design it so the ways it may be used are limited, this is called affordance by Norman.

When I worked on the design of televisions, I immediately ran into the idea of affordance. A television motherboard and its chassis were dropped off in my lab, but about seven cables had been disconnected. I protested that it was all apart, and was calmly told by a technician  that all the plugs would only go into one place on the motherboard. Indeed, they did, and I was impressed that because of this affordance, I couldn’t make a mistake.

The affordance of the TV motherboard was essentially foolproof, but often designers can’t restrict a user that much, and the affordance involves only discomfort or a subtle tactile clue. Donald Norman offers this:

Take another example of good design. My felt-tipped marking pen has ribs along only one of its sides; otherwise all sides look identical. Careful examination shows that the tip of the marker is angled and makes the best line if the marker is held with the ribbed side up, a natural result if the forefinger rests upon the ribs. No harm results if I hold the marker another way, but the marker writes less well. The ribs are subtle design cue—functional, yet visibly and aesthetically unobtrusive.

Norman also shows numerous door handles as examples. If we see only a push plate on a door, we have no other choice but to push to open the door. A handle which one can readily grasp cues us that we pull to open it. This brings us back to the measuring cup shown above. Its design is pro-metric, as the metric graduations are facing a person’s eyes when it is held with the right hand. About 70-90% of the worlds population are right handed. Right handed Americans using this measuring cup, would find it uncomfortable and unnatural to place the handle on the left. The measuring cup shown is from the period when the US pretended it might go metric. Measuring cups of this same type, which are currently sold in the US, are all designed so that the imperial graduations face one’s eyes when held with the handle on the right. One of mine is shown below:

Common American Measuring Cup

Measuring cup designs have improved since the 1970s. Some of the ones I now own are “top readable” and only sold (unfortunately) at product parties. Dual scale is always a hindrance to metric adoption, but this set of top reading measuring cups are the best I have encountered.  I have visited many cooking stores and looked online, but have yet to find metric-only measuring cups and measuring spoons. The measuring cup shown below appears to have eliminated a right hand bias as well as being easy to read. Now if I could just purchase a metric-only one.

Top Read Measuring Vessel with Clear Metric Graduations
Left Handed Ruler

The design of common measuring cups is but one example of subtle anti-metric bias in our everyday things. In a previous blog I mentioned that the design of American “metric” rulers hinders their use because of the presence of a centimeter-millimeter dual unit scale, and the rounding of the origin end of one particular metric scale. The origin of the inch scale is placed on the square end, which is much more natural for measuring. For about 10% of our population, which are left-handed, the current dual scale measuring cups are adequately designed for metric use. On the other hand both metric and inch ruler scales  have equally low affordance for left-handed people. Left hand rulers exist which have the numbering from right to left to increase the ease of use by a left handed person.

My father gave me an expandable wrench for my last birthday, which has mm markings on one side, and had inch on the other (yes, I ground off the inch scale). If one holds the wrench as a right handed person would, the inch scale faces your eyes. On the opposite side is the metric scale, which has low affordance for a right-handed person. The wrench is nice because it allows one to immediately see what size a bolt head is in mm, but it is very cumbersome for me to use, as I’m right handed.. I have a better understanding of what left handed people deal with on an everyday basis in our world.

Expandible wrench designed with an affordability preference for inches (click to enlarge)

These examples point to the fact that a preference for imperial measures is designed into our US tools, and US everyday things. But I’ve been assured by non-binding legislation that the US prefers metric measurements. Here is some background:

The Omnibus Trade and Competitiveness Act of 1988 was signed into law by Ronald Reagan. It amended the Metric Conversion Act of 1975, yet didn’t have the word metric in the title of the legislation. President Reagan and Congress apparently were concerned that the voluntary nature of the Metric Conversion Act of 1975 was not clear enough.

Section 3 of the Metric Conversion Act of 1975 is amended to read as follows:

SEC. 3. It is therefore the declared policy of the United States

(1) to designate the metric system of measurement as the preferred system of weights and measures for United States trade and commerce;

(2) to require that each Federal agency, by a date certain and to the extent economically feasible by the end of the fiscal year 1992, use the metric system of measurement in its procurement, grants, and other business-related activities, Except to the extent that such use is impractical or is likely to cause significant inefficiencies or loss of markets to United States firms, such as when foreign competitors are producing competing products in non-metric units;

Well, it has been the case since the 19th Century, that switching to metric is always “impractical” in the US. Apparently there was much concern among our legislators that we have an exception: “such as when foreign competitors are producing competing products in non-metric units;” Apparently Liberia and Myanmar (the last two non-metric holdouts in the world) might flood the US (and the world?) with non-metric products, and thereby destroy what’s left of our uncompetitive non-metric US economy. Thank you President Reagan and Congress for the foresight to see the threat and protect us from the economic danger posed by these two tiny countries, and making an exception. Clearly the 1992 date was meaningless and arbitrary. It made it look like the government was taking action, when in fact it was not. Metric is 21 years past the expiration date for becoming “preferred.”

One can easily see how “preferred” metric is in the US simply by inspecting the design of our everyday things and everyday tools. The legislation is feckless, and crass hypocrisy. It is in line with the strange belief that if we cling onto the trappings of our past, the future may be indefinitely postponed. This emotional response, written in legislation, only postpones the day when reality intervenes, and forces Americans to realize that fantasy is no match for reality. I’m not willing to wait another 150 years hoping America will come to its senses. We need legislation that compels industry to design and make available true metric products, during a short compulsory switchover by industry, government, and education to metric. What we have now is legislation celebrating the the metric system as the preferred system of the future and makes sure it will always remain so.

Related Essay:

The Invisible Metric Embargo

If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is not of direct importance to metric education. It is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.

Stealth Imperial in The Kitchen

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By The Metric Maven

Bulldog Edition

Some years back a technician, with whom I worked, gave me a birthday present which I still have. He is a numismatic enthusiast and the present was a cased set of US coins. It has 1 cent, 5 cent, 10 cent, 25 cent, 50 cent and 100 cent coins. Whenever I look at the set, I always think of Sesame Street’s game where they sing a song and ask which of these things is not like the other, which of these things doesn’t belong? Well do you have any idea which of these coins doesn’t belong? Here is the set I was given some years ago:

Now to help you, here are coins used by the EU:

See the one that doesn’t match? Yes, the Euro has a 20 cent coin and not a 25 cent coin. There is no EU equivalent. Why is this? Well most people think that decimalized US currency was adopted with open arms—not so. There were reactionaries that didn’t like this “metric money” stuff and would only allow decimalized currency if it included a 25 cent coin. This compromise allowed the US to become the first country with a decimalized currency. The quarter was insisted upon so the US dollar could be divided in fourths, which corresponds to divisions of the original Spanish dollar which could be divided by up to eight. Hence the jingle: “two bits, four bits, six bits a dollar all for [insert school name here] stand up and holler!” which is repeated at High School Basketball games all over the US each year. Think about what we call the coin. We call it a quarter (1/4) or a twenty five cent piece.. My Grandfather on my mothers side always called a quarter two-bits.

Chances are fairly good that you never noticed this imposition of a non-decimal currency value onto our decimalized money. It’s there, but we just work with it each day, without a clue to its origin, or even taking notice.

When I began metric cooking, I immediately adopted the idea that a teaspoon was 5 mL and a tablespoon was 15 mL. I also used a 1/2 teaspoon or 2.5 mL or a 1/4 teaspoon which is 1.25 mL without giving the measurement spoons much thought. When I began putting together a metric cookbook it slowly sank in, that there were no good “metric equivalents” for the Tsp and Tbl written in recipes. That is, there are no modular values or integer values.  I would see 2 1/2 teaspoons and it would become 12.5 mL. This is true, but doesn’t seem to give you an immediate idea of how many of each measuring spoon one should use. It gradually struck me that what had occurred with my metric cooking was an attempt to “metricate” traditional imperial cooking measures, rather than starting from scratch. And we all know cooking from scratch is also the best way. The volumes of measuring spoons were not chosen in a rational manner using “Preferred Numbers,” (I will have a blog on this in the future) but had been chosen by convention and transmitted by tradition. Because of this, their origins are a mystery, and no one can explain why it was done—they just were. Perhaps three teaspoons in a tablespoon like three barleycorn to an inch?—no, probably too logical.

I quickly realized that to my knowledge, there has never been a set of “metric” measuring spoons created. It was clear to me that this would probably consist of a set of 1 mL 2 mL, 5 mL, 10 mL, 20 mL and 50 mL measuring spoons. This would eliminate the need for a decimal point when using metric measurements. In the case of my 12.5 mL value, I could round up to 13 and use a 1, 2 and 10 mL spoon, or down to 12 and only need 2 and 10 mL spoons. These would be very close to the current measurement values of 1/4 tsp (1.25 mL), 1/2 tsp (2.5 mL), 1 tsp (5.0 mL), and 1 tbl (15 mL) that cooks could convert without too much difficulty. One could also have an optional 100 μL, 200 μL, 500μL set of spoons. Using Naughtin’s Laws one can be certain that the mL and μL would not be easily confused in a recipe. Not even the Australians have metricated their spoon cooking measures. When Australia decided to convert to metric, cooking was exempted. As Kevin Wilkes relates in Metrication in Australia:

Domestic cookery scales were exempted from the prohibition of imperially marked measuring instruments, but the decision by the cookery sector committee to recommend the use of cup and spoon measures meant that most writers of recipes adopted this system, Thus obviating much of the need for metric cooking scales.

***

Spoon measures were unchanged, the existing standard having defined a tablespoon as 20 mL [15 mL in the US] and the teaspoon as 5 mL, but a metric cup of 250 mL was adopted to replace the existing eight fluid ounce measure which was equal to 227 mL

In the conversion of existing recipes, 30 g was adopted as the equivalent of one oz and 30 mL as the equivalent of one fl oz.(tip of the hat to Klystron for providing this information)

Metric cups!  Metric spoons!  Metric ounces! I’ve written about the idea of the use of metric as a modifier for imperial measures. They are ridiculous oxymoron units. I have also written about how the Tsp and Tbl are killers. An Australian teaspoon is 20 mL and in the US it’s 15 mL. The introduction of metric measurement spoons of 1, 2, 5, 10, 20 and 50 mL, would eliminate this disparity and directly use only mL, instead of employing an antiquated proxy unit like teaspoons and tablespoons. It would allow for an international cooking standard to be created.

What truly shows the wasted metrication opportunities and material we will tolerate, and which many people apparently also find entertaining, is a set of “measurement spoons” like these:

click on image to enlarge

One set came “free” with a set of measuring spoons I ordered. The other was a Christmas present I received this year. They are obviously a joke novelty, but the effort was made to manufacture them rather than offering a metric-only 1, 2, 5, 10, 20, 50 mL set of cooking spoons as an alternative. The measuring spoons above are functional, but are never meant for any actual use I suspect, as I do not believe most people commonly use a pinch, tad, smidgeon, nip or dash these days. Nor, I suspect, is there common agreement on each value. I’m sure there are “scads” of definitions. These “units” are good example of unit proliferation. It would be far better to offer a “free” metric set of spoons in place of the novelty ones. I have written about the opportunity for the medical mis-dosage of people because of the teaspoon-tablespoon abbreviation confusion before. If most homes had a “metric set” of measuring spoons, which came with the common imperial ones, people would have the option to directly use mL, even if a dosage cup was not provided on a medicine—or was lost.

During a US metric switch-over, the implementation of a logical set of measuring spoons for cooking, would be a good way to break with the past, and make cooking more accurate and consistent. With metric cooking spoons we could lead the world in metrication instead of bringing up the rear.

If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is not of direct importance to metric education. It is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.