This post is simply to show you the physical sizes of some dominoes. Size is subjective for many, I have a mental image of the size of my phone, however if I put it in a case for an extended period of time then take it out of the case it seems so small because the size of the case has altered my mental image of the size of the phone.
Dominoes have a feel in your hand…
Dominoes are the same way, you have a favorite set and know how heavy they feel and how big they are in your hand but when you go looking online for something the same size, how do you know if you do not have a caliper (as seen in the pictures here) .
How thick is a domino?
Let us start with thickness, the dominoes are about .45 inches thick, excluding the brass spinner that makes the spinner style a bit thicker overall. If you can picture .45 inches, that is great, if not then how about 5 US quarters + a dime? if you stack the quarters only then they feel just a bit short of the dominoes, when you add the dime they feel the same.
Thickness of 5 quarters + 1 dime 
thickness of a non-spinner white domino 
thickness of a white domino with spinners
How tall and wide are dominoes?
Now on to the height and width – you can interchange these because you may hold the domino in landscape or portrait mode (wide or tall). For this I will be considering them as tall. Typically the tournament size are 1.1 x 2.2 inches and the jumbo size are 1.05 x 2.2 inches. As before, if you want to see pictures here they are. The calipers are clearly visible so you can read the measurements to any precision that you would like.
What is with the manual caliper?
I used an analog caliper for these pictures because you can see the measurements in three places – along the silver bar, in the white dial if you relate to fractions of inches, and in the green dial if you prefer decimal measurements. This seemed to be the best idea for pictures.
I use the decimal notations in this post simply because when typing they are less likely to be mistyped or misinterpreted.
When working with the lasers at EngravedDominoes.com, we typically use an electronic caliper so that the numbers can simply be read into the computers that run the lasers. The manual one is here as a backup if we run out of batteries or all the electronic ones are being used at the time and it happened to be very photogenic.