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Donald Hillger


Under the Hood, We’re Metric

Celebrating 100 years of the U.S. Metric Association

Published: Tuesday, November 1, 2016 - 16:32

This year, 2016, marks the 100th anniversary of the founding of the U.S. Metric Association (USMA). Our mission is to help the United States complete its transition to the metric system. Although we’ve always expected that the adoption of the metric system here was just around the corner, all these years later we find we’re still working for the metric cause.

I joined the USMA in the early 1980s. Like many citizens, I had been mostly unaware of the worldwide move to metric, mainly in the former British Commonwealth countries: Australia, Canada, New Zealand, South Africa, etc. At the time, metric-adopting countries followed through on their planned transitions without a hitch, according to schedules and deadlines for national metric changes. The United States considered following suit but didn’t exclusively adopt metric to the extent necessary to complete the job.

Although many companies and certain industries have recognized the benefits of converting to metric, such as its simplicity and the streamlined access it gives them to global markets and supply lines, no one would really consider the United States to be a metric country.

But metric usage in the United States is more common than most citizens realize. From automobiles and machinery and medical fields, to nearly everything made in China or the rest of the world, which is a lot these days, metric is everywhere.

It’s true that much of our metric usage is behind the scenes, but it’s not completely hidden from the observant citizen. Take a typical car speedometer that gives readings in both miles and kilometers per hour (in smaller font). While this feature gives you the impression that the car is standarized through and through, the truth is that the car was designed and built using metric measurements. This is a good metaphor for the state of metric in the America: Under the hood we’re metric; it’s the part that people see that isn’t.

What I think we need to do is bring metric out of the shadows, stop converting and start conversing in metric. We need to begin using metric in the way that metric countries do, e.g., on road signs, in weather reports, and at the grocery store.

Image: Overdosing can be dangerous, and underdosing is ineffective. For the most accurate dosing, ask for and use metric measures. Credit: Koerty van Ittersum/Brian Wansink/Cornell University

While we’re not there yet, opportunities exist for people like you and me who want to see more metric use in everyday life. Let’s ask for more metric units in media. Let’s simplify product packaging labels to list only metric quantities. Let’s prevent medical dosage errors by using only milliliters, not tablespoons or teaspoons. Let’s help children build familiarity in metric by providing daily opportunities to practice using metric measures as much as they can, at both home and school.

USMA has a number of programs to help in the U.S. metric transition. Besides basic metric information, our website has a section on the laws related to the metric system covering the past 100 years, showing where the United States stands legislatively. We also have a ton of information showing metric use in food and other product labeling.

As far as tools and suggestions for members and the public, we have a metric guide , as well as just the basics. If you want to teach metric or consult with businesses, we offer training to make you a metric expert. There’s a large science fair award program to honor students who use metric units especially well in their science projects. Teachers can also download materials for them to use in their classrooms.

We regularly publish a newsletter, Metric Today, that keeps our members informed of metric advances in the United States, as well as stories of metric use that otherwise are not apparent to the average citizen.

The adoption of the metric system in the United States is inevitable. Many advances are taking place, slowly but surely. The metric system is not something that was tried here and failed: It’s just taking longer than most metric advocates would like. We can’t predict when we’ll see metric road signs and weather reports, and those may be among the last things to change, but we can quicken the pace of that change by conversing in metric. In the meantime, my colleagues and I at the USMA and our supporters will continue to pursue a metric United States because we believe that the adoption of the metric system is in the best interests of this country and its citizens.

First published Oct. 13, 2016, on NIST’s Taking Measure blog.


About The Author

Donald Hillger’s picture

Donald Hillger

Donald Hillger, research scientist, is president of the U.S. Metric Association and a National Oceanic and Atmospheric Administration (NOAA) meteorologist stationed at the Cooperative Institute for Research in the Atmosphere at Colorado State University. He’s also a philatelist with numerous publications on postage stamps, the metric system, and amateur radio. Hillger has a bachelor’s degree in physics, and a master’s degree and Ph.D. in atmospheric science. Hillger specializes in satellite meteorology from geostationary and polar-orbiting platforms, as well as satellite instrument calibration/validation, satellite data/image quality, and planning for advanced and future instrumentation.



I could not agree more.  So many measurements we use in everyday life are nominal or have such large tolerances that metric vs. traditional is meaningless.  Is a 2x4 going to become something different if we decide that it is now a 50x100 or a 38x88 or something else - none of which will be an actual accurate measurement of the wood's cross-sectional perimeter.  We certainly are not going to start using different sizes of wood that would then be impossible to retro-fit into existing structures.  Does it make a difference if we load a pick up with a cubic yard or a cubic meter of mulch?  In any case, the loader operator is still going only put as much in our truck as his loader bucket will hold.  It may be a yard and a half - it may only be half a yard.  Are owners of real property going to be better served if they now own a fractional hectare instead of a fractional acre?  Are county clerks, title agents and land surveyors going to be able to accurately convert all the property transfers into hectare units on the new recordings and who is going to bear the burden for the inevitable errors?

I use both measurement systems everyday.  All measurement systems are absolutely arbitrary and none are any more accurate than any others - provided that you use accurate or calibrated measuring devices.  You don't want to be like the guy who polished the Hubble's mirror and assumed (just because his data said so) he had exceeded the theoretical reflectivity of glass without going back and recalibrating his reflectometer.  Feet and inches are certainly must easier to estimate w/o a measuring device, and as a carpenter, it is much easier to think in terms of halves, quarters and thirty-seconds than it is to think in terms of tenths of anything.  Yes, it is easier to do calculations with decimal fractions and yes, it is easier to scale up and down a unit system that was designed as a unified system.  So what?  If you can't do fractions in your head, you aren't worried about measuring anything to begin with.  Likewise for simple memorization.  

In our lab we use metric for most liquid measures and most measures of mass less than a kilo.  Above a kilo we go to customary units and use balances calibrated in tenths of pounds.  Measurements of length are all decimal however the units used, SI or customary, are dependent upon the specification dimensions for the product.  There is absolutely no reason why both systems cannot coexist in their own spheres, nor is there any necessity why either should supplant the other where it would not be an improvement.  

Bah Humbug

I am a degreed physicist that doesn't work in the field. (Just to show my age that was back in 1970) So I am familiar with metric measurements.  As for temperature, fuel, drinks, distances, what difference does it make?  Miles, feet, pounds, etc. are ingrained by usage, true.  But in the end what difference does it make to go 11 miles or ? kilometers to work or to grandmother's house, etc.  I know electrical measurements, and many other items are metric, but for football fileds, baseball diamonds, weights, etc. why change?  To me it is confusing to say something weighs a kilogram when I was taught that kilograms are a measure of mass, and that a kilogram is a kilgram no matter whether you are on the moon, Earth or Jupiter.  I don't really know if they are using a Kg for weight because no one over 40 will probably ever leave this planet.  But if you wat to get technical, that Kg of weight is not the same all over the Earth either, because of differences in gravitational acceleration.  Might not be significant, but it will be different. 

Sure, I don't know how many tsp in a Tsp or a cup, but I can look that up as well.  I do know how many ml in a L, but converting that to volume in cc is not consistent unless you are talking water.  Are we going to change our measure from sq. ft./sq. yd. to sq. m?  Carpeting or housing would work fine, but the wall studs are 8 foot, not 2.5 m or so, that will have to change when we go metric.. It might be easier to measure land in sq Km, in lieu of acres, because acres is not an easy measurement, sq miles is.  How about the layout of this country?  It is laid out on the sq. mile--most county roads are a mile apart in either direction (at least in the great plains states), city blocks are laid out in foot measure as well with approximately 15 blocks to the mile is that 13 or 14 blocks to the Km?  Who is going to re-measure all that just to make you happy?  Who will pay for it?

A lot has to be thought out before mass conversion.  Temperatures for the weather have no need to be in Celsius vs Fahrenhiet, why not go to degeres Kelvin  have everyone feeling hot at 273 deg K. when it is just 32 deg F, or 0 deg C,  inches of rain vs. cm, etc.  To us old fogeys that 0 is considered cold not just a cool 32 .  Why?  What difference does it make to spend so much money needlessly?  Just so some one can say we are consistent with other countries?

In the end it will cost lots of money to change all the road signs, someone has to convert those miles to Km or re-measure everything.  Money that can be spent elsewhere on more fruitful endeavors--like fixing bridges, or the roads themselves, than change for change sake.  Most medicines that have a dosage provide a small cup with the right dosage maked on them already.  Change all gasoline pumps to read Liters instead of gallons and to price per liter or get a 4 liter designation to make it feel the same, switching from $/gallon to Cents per liter would relly be confusing, all the tax rates would have to be changed.  Maybe we don't want to be a one world order.  It is true that the Imperial gallon is different than the US Gallon, and weights are different in other non-metric measures.  They are in the process of redefining all of the Metric System measures, too.  How will that affect the public? 

I hope I have corrected all my typing mistakes, and if not, at least my rant is readable.