# alcohol content of liquor: why do Americans use "proof" and Canadians use percentage? **URL:** \ **Category:** Factual Questions\ **Created:** [July 10, 2018, 1:40am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631 "2018-07-10T01:40:38Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [July 10, 2018, 1:40am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/1 "2018-07-10T01:40:38Z")
and what’s the difference, anyway? 😕 ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [July 10, 2018, 1:48am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/2 "2018-07-10T01:48:45Z")
“Proof” has something to do with how easily you can start a fire with it or something. You halve proof to get percentage. Thus, 40 proof is 20 percent alcohol by volume. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [July 10, 2018, 1:49am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/3 "2018-07-10T01:49:49Z")
Hmm. Well, 40% alcohol is 80 proof. It’s always double the alcohol percentage. I believe we used to use proof here at one time, but I’m not sure since I grew up on a border town. Does anyone really label bottles with proof anymore? ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [July 10, 2018, 2:25am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/4 "2018-07-10T02:25:03Z")
Wikipedia — > [@](#): > > The term proof dates back to 16th century England, when spirits were taxed at different rates depending on their alcohol content. Spirits were tested by soaking a pellet of gunpowder in them. If the gunpowder could still burn, the spirits were rated above proof and taxed at a higher rate.[1] As gunpowder would not burn if soaked in rum that contained less than 57.15% ABV, rum that contained this percentage of alcohol was defined as having 100 degrees proof. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [July 10, 2018, 2:34am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/5 "2018-07-10T02:34:36Z")
> [@Leaffan](#): > > Hmm. Well, 40% alcohol is 80 proof. It’s always double the alcohol percentage. I believe we used to use proof here at one time, but I’m not sure since I grew up on a border town. > > Does anyone really label bottles with proof anymore? The vodka in the freezer has both. “40% Alcohol By Volume (80 Proof)” ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [July 10, 2018, 2:57am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/6 "2018-07-10T02:57:57Z")
No proof on my bottle of Smirnoff: % only. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [July 10, 2018, 8:36am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/7 "2018-07-10T08:36:49Z")
Europe uses percentage by volume (alcohol by volume (ABV))everywhere these days. ---
**Author:** ![Fleetwood](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fleetwood/32/271_2.png) [@Fleetwood](https://boards.straightdope.com/u/Fleetwood)\ **Post date:** [July 10, 2018, 10:37am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/8 "2018-07-10T10:37:50Z")
Looking at a bottle of Tullamore Dew (blended Irish whiskey) - Has ABV 40% listed but no proof. Bought last month in New Hampshire. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [July 10, 2018, 11:10am UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/9 "2018-07-10T11:10:50Z")
Same reasons the US still uses Imperial when the rest of the world uses Metric, I’d guess - cultural inertia being the largest factor, no doubt. Plus some irrationality - if you switch from “80 Proof” to “40%”, it will probably feel like you’re being shortchanged, somehow, just because the number got smaller. Pretty sure nobody uses proof for beer and wine, though, so it’s not like ABV isn’t already used in the US. ---
**Author:** ![Bonzi](https://avatars.discourse-cdn.com/v4/letter/b/838e76/32.png) [@Bonzi](https://boards.straightdope.com/u/Bonzi)\ **Post date:** [July 10, 2018, 12:35pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/10 "2018-07-10T12:35:28Z")
Actually, in the Craft Beer world, percentage i used exclusively… ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [July 10, 2018, 1:15pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/11 "2018-07-10T13:15:38Z")
> [@Leaffan](#): > > No proof on my bottle of Smirnoff: % only. I suspect labels will vary by location. Here in the US, proof is still commonly on bottles. ---
**Author:** ![digs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/digs/32/14889_2.png) [@digs](https://boards.straightdope.com/u/digs)\ **Post date:** [July 10, 2018, 1:21pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/12 "2018-07-10T13:21:21Z")
> [@bob\_2](#): > > Europe uses percentage by volume (alcohol by volume (ABV))everywhere these days. Had a drink at a restaurant named **ABV** the other day. Sounds cooler than **Proof**. ---
**Author:** ![Dickerman](https://avatars.discourse-cdn.com/v4/letter/d/8baadc/32.png) [@Dickerman](https://boards.straightdope.com/u/Dickerman)\ **Post date:** [July 10, 2018, 1:42pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/13 "2018-07-10T13:42:29Z")
In the US, ABV is required for distilled spirits: [https://www.ecfr.gov/cgi-bin/text-idx?SID=07c4ec70d2c2dc7d75796ade19d63d08&mc=true&node=se27.1.5\_137&rgn=div8](https://www.ecfr.gov/cgi-bin/text-idx?SID=07c4ec70d2c2dc7d75796ade19d63d08&mc=true&node=se27.1.5_137&rgn=div8) whereas proof is optional. It differs for malt beverages, and wine, ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [July 10, 2018, 2:40pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/14 "2018-07-10T14:40:30Z")
> [@MrDibble](#): > > Same reasons the US still uses Imperial when the rest of the world uses Metric, Interestingly, liquor bottles are all metric. And every bottle I’ve seen is either just percentage, or has both percentage and proof. I think they’re legally required to print the ABV% on the bottle, while proof is more of a cultural holdover, like \*\*Dickerman \*\*says. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [July 10, 2018, 3:12pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/15 "2018-07-10T15:12:34Z")
> [@bump](#): > > Interestingly, liquor bottles are all metric. Yep. The sizes are all in metric, but the common or nicknames can still be their imperial forebears. We’ve had this thread before, but a 750mL is still called a “fifth” in many parts of the US (it’s the standard term in my location and age group, at least). The 375mL is called a “pint” and the 250mL is called a “half pint.” And the 1.5L is a “handle.” But, yes, all in metric. Wine is metric, too, but beer and malt beverages are usually imperial units, unless they’re imports. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [July 10, 2018, 3:40pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/16 "2018-07-10T15:40:49Z")
Has beer, wine and lower alcohol content beverages ever been labelled with their proofiness? My initial assumption is labeling beers and wines with alcohol content is a relatively recent development, but I’m just guessing here. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [July 10, 2018, 4:39pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/17 "2018-07-10T16:39:24Z")
Yes, if you read the Wikipedia article, originally proof was expressed as the weight of alcohol vs. water in the beverage; which was not directly 1/2 and alcohol of course weighs less than water. It was probably a meaningful measure in the old days when equipment for measuring alcohol content were less precise - just weigh a known volume to get proof. Eventually it was simpler and more meaningful to use % volume. ---
**Author:** ![Orwell](https://avatars.discourse-cdn.com/v4/letter/o/dfb087/32.png) [@Orwell](https://boards.straightdope.com/u/Orwell)\ **Post date:** [July 10, 2018, 5:53pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/18 "2018-07-10T17:53:56Z")
> [@pulykamell](#): > > Yep. The sizes are all in metric, but the common or nicknames can still be their imperial forebears. We’ve had this thread before, but a 750mL is still called a “fifth” in many parts of the US (it’s the standard term in my location and age group, at least). The 375mL is called a “pint” and the 250mL is called a “half pint.” And the 1.5L is a “handle.” “Handles” (the term favored by young’uns) are also called “half gallons” (mostly by oldsters). They contain 1.75L, not 1.5 as you indicated. 1.75 liters is 0.46 gallons, so it’s reasonably close to a half gallon. A 750 ML “fifth” contains 0.1981 gallons, so it is indeed very close to a fifth of a gallon. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [July 10, 2018, 6:24pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/19 "2018-07-10T18:24:07Z")
> [@Orwell](#): > > They contain 1.75L, not 1.5 as you indicated. . _smack_ I really did know that! Brain fart. Anyhow, I just looked around while I was out shopping and from what I can see, it’s not even consistent within which brand ABV and Proof is printed, or just ABV. Half the Smirnoff products had ABV only. The other had ABV and proof. (It seems to me like there’s an older and newer labeling. The ones with “Recipe No. 21” on the label had ABV only. The ones without had ABV and proof.) Stolichnaya had ABV and proof. Sobieski had ABV and proof. Seagrams gin had ABV and proof as did Bombay and Bombay Sapphire. The regular Malibu spiced rum only had ABV, but the black had the [proof prominently displayed](https://applejack.com/site/images/Malibu-Black-Rum-175-l_1.png) (larger than the ABV number). And, of course, we have stuff like Bacardi 151 or Southern Comfort 100 proof or Wild Turkey 101, which has the proof in the name. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [July 10, 2018, 6:37pm UTC](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631/20 "2018-07-10T18:37:23Z")
> [@MrDibble](#): > > Same reasons the US still uses Imperial when the rest of the world uses Metric, I’d guess - cultural inertia being the largest factor, no doubt. Plus some irrationality - if you switch from “80 Proof” to “40%”, it will probably feel like you’re being shortchanged, somehow, just because the number got smaller. > > Pretty sure nobody uses proof for beer and wine, though, so it’s not like ABV isn’t already used in the US. The UK uses Imperial (yes, still, in manu cases). The US does not, it uses US Customary. The two systems are mostly the same, but one area where they are markedly different are in liquid measures. And IIRC the US requires the mL to be stated, even if measured in oz. For hard alcohol that is not a concern though, as all measurements are metric, and only given customary nicknames (a fifth is officially 750 mL, but 1/5 gallon is really 757 mL). You are required to put ABV on the bottle, proof is optional and is a historical affectation, just like how Canadian whisky can be labeled rye whisky and have 0% rye grain involved. BTW, proof = ABV x 2 is not the only definition. The UK used ABV x 1.75, but that system is obsolete. [Next page](https://boards.straightdope.com/t/alcohol-content-of-liquor-why-do-americans-use-proof-and-canadians-use-percentage/817631.md?page=2)