# Lumber in Metric Countries

I’ve always wondered how lumber is dimensioned in the metric world.

plywood is 4 x 8 feet and typically 5/8 or 3/4 inch thick.

lumber 2 x 4, 2 x 6, 2 x 8, or 2 x 10

studs are framed on 16 inch centers

If I went to England, France or other metric countries what’s available in the store?

I can partly answer: in Australia the normal size for a sheet of plywood is 1200 mm by 2400 mm. The old nominal sizes based on inches were generally converted at the rate of 25 mm to the inch, so the nominal equivalent of 2 by 4 inches is 50 x 100 mm, though what you actually get is closer to 40 x 90 mm.

All building and carpentry dimensions are given in mm, so if you just see “150” on a plan, you know that’s about 6 inches, and not 150 inches or 150 metres.

This is how we buy it in the UK (England) :- B&Q

In Canada, lumber size is expressed in inches.

Not strictly; although b&q give the sizes in mm on their website, I’d say it’s a fairly rare occurrence for someone to walk into a builders merchants asking for “3600mm of 38 by 19”, but rather more common to simply refer to it as “12 foot of 1 by 2”
Whenever I’ve bought wood (semi-regularly, I do a bit of carpentry in my spare time) it is discussed verbally in imperial units, but printed on the receipt in metric, though not rounded like Giles mentions, a board of ply would be 2438 x 1219 (I think, can I trust google conversions?).

Also Giles, the measurements lumber is sold by are the rough cut dimensions, before planing, which accounts for the discrepancy you mentioned.

In New Zealand, plywood is 1200 x 2400 mm and
3ply 4mm, 7mm, 9mm
5ply 12mm (1/2"), 15mm
7ply 17mm (5/8"), 19mm (3/4"), 21mm
9ply 25mm (1")
11ply 33mm (1 1/2")

Timber 50 x 100, 50 x 150, 50 x 200, 50 x 300 (Equivalents of what is in your question)

Stud framing is 400 mm centres.

A friend of mine speaks Norwegian. He went into a lumber yard in Oslo and asked for a piece of wood 5cm by 10cm and heard the clerk call to the back room for a 2x4. Of course, these sizes are nominal in any case. A 2x4 might be 1 1/2 by 3 1/4 or something of the sort. A 4 by 8 sheet of plywood is actually 4 foot by 8 foot, exactly.

And yes, in Canada, even though nearly everything else is strictly metric, wood is still sold in imperial units.

Football fields are still 110 yards long with 20 yard endzones and, IIRC correctly 65 yards wide. These differ from US football of course, but are not metric. And you still have to go 10 yards for a first down. And the distance between bases is still 90 feet and the pitcher’s rubber is 60’6" from home. The specs on a curling rink are given in feet and I don’t think this is ever likely to change.

As far as I know the lumber industry in Sweden uses inches.

It’s sold and labeled in metric, but the dimensions correspond to and are often referred to in old measures. Norway’s been metric for over a hundred years, but the labeling of lumber dimensions in metric only goes back a few decades. I’ve never heard the length mentioned in feet and/or inches though, in my 35 years of living.

Here’s from the website of a major DIY/construction-store:

Price is NOK per meter length, the list at the bottom is of “other common dimensions”.

This site only lists lumber dimensions in metric: Beijerbygg

I’d guess the lumber industry in Sweden, as in Norway, often use the closest approximation in inches colloquially, but that everything is officially made, labeled and sold in metric.

I’d say that people are still getting accustomed to using the metric system and there is a strong generational gap to this. Those above a certain age still use the old imperial system in conversational speech, while those young enough to have only known metric have little idea what the heck 80 degrees feels like.

Oddly I’ve noticed that everybody seems to use Feet/Inches/Pounds to describe **themselves **but would use kg/km to describe all other forms of weight/distance.

ex: “I’m 5’11” tall and 165 lbs, but I want a 2kg bag of flour from the market 40km away"

bizarre… (and lets not get into the mishmash spelling differences Canadians choose between UK-English and US-English: “colour”=correct, “Tyre”=incorrect)

And a 4x8 sheet of 3/4" thick plywood is slightly less than 3/4" thick.

In Australia, TVs and computer screens are still sold by inches, or if they’re advertised in metric, they’ll have the imperial measurement somewhere prominent- despite the fact Australia has been a metric country for over half a century.

It might seem that long, but the conversion to the metric system in Australia took place during the 1970s and 1980s.

Same here(Sweden) and we went metric before the TV had even been invented.
Of course, most people probably don’t have a clue what the number actually mean, only that the bigger it is, the larger the TV.

And even then, a modern 2 x 4 is smaller than an old 2 x 4 because it used to be that the size of the board was the actual size of the finished board, whereas with more modern boards the size of the board includes not just the board but also the space where the board had shrunk during drying and the space where the board had been planed, starting with a 2 x 4 sawn from the log but eventually leaving you with 1 1/2 x 3 1/2 finished board.

Thanks! I tried to find one single site that told me what dimensions they used but after the first ten I gave up. However, as I’m typing this I have made a quick search for nails and found both inches and millimeters.

The historical background for using inches is that USA is/was a large market so it was a practical thing to do it that way.

BTW it was the Swedish inventor and industrialist Carl Edvard Johansson, “Mått-Johansson”, who once and for all decided the length of an inch. Before he did there were several different measures called inch (tum, =thumb, in Swedish) in use in different countries (and industries?) and he had to make several different measuring instruments depending on the markets, so he just said that from now (then?) on he would use one standard inch and his customers had to comply.

Well, Germany has (naturally) a DIN norm for this. The general usage (IANALumberjack) is metric: when I go into my DIY market, the wood is lettered in cm. and getting it cut to a specific size, the square area is calculated, because the price is per square meter.

Hereis a German-language table of dimensions (and lot of other information about wood).

dimensions of lumber (= wood used for building things); Latte = small 2x4, Brett = flat board, Bohle = floor board, Kantholz = big 2x4. First number is thickness d or height h, second is width b, all in mm. 10 mm = 1 cm. 2.5 cm = 1 inch

Drawings of the several types here.

The only use of inches (Zoll) seems to be in the building industry, because wood frame houses went out of fashion for a while and apparently were imported back from the US, so they use 16 in. as the standard distance from one beam to the next.

Could furnish French equivalents, but Constanze did it for Germany, with a bit of European Standard jostling, and some local habits, DIN sizes are EU constants
changes do include things like new difficulties finding large format plywood (3200 x 1530mm, even 2400 x 2040mm) because they are considered too heavy for workers, (2500 x 1220mm) being accepted. Plywood thickness is now 5,10,15,18,22mm, Medium(fine particle board) is 13,16,22mm
Wood construction is still an exception in France, most solid dimensions are roofing sizes.

You’ve hit on one of the biggest pains in the ass for Canada and our incomplete metric conversion. You basically need to bring your measurements and a calculator with you to the hardware store because half the measurements will be inches and half will be centimeters. I do some landscape designing, and I do all my design work in metric because it’s so easy to work with, then when the design gets installed in the real world, my half meter wide path has to get adapted to concrete pavers in inches and feet.