I have seen many people say that “the drills are much smaller than I thought” once they got their Diamond Painting kit. The next question is how big are the drills. Here I am going to write a bit about just this. What is the size of the different types of drills used in Diamond Painting.
Square drills
The square drills are 0.25×0.25 cm in size, or if you find it easier to read it in millimeters, it will be 2.5 x 2.5. For the ones of you that like inches it is about 0,098 by 0,098 inches. If you place four square drills next to each other, you will reach one centimeter. As you can understand, they are very small.

Round drills
The round drills are slightly larger than the square ones, and have a size of 0.28×0.28 cm. Which in millimeters will be 2.8×2.8. In inches it is about 0,11 by 0,11. If you place 4 round drills next to each other, you will reach 1.12 centimeters. So the round drills are not particularly large either, although they are marginally larger than the square ones.

Rhinestone drills
Rhinestone drills are usually round and are the same size as the regular round drills. That is, they are 0.28×0.28 cm large (or small, depending on how you want to see it).

Special shaped drills
The special shaped drills come in all possible shapes and sizes. I have had one painting that had star-shaped drills, and another that had drills shaped like snowflakes. I have also seen square rhinestone drills, but they have been larger than the usual square drills. There are really a lot of different ones and it is therefore difficult to answer the question “how big are the drills”. In the picture below you can see some of the ones I have gotten and used on paintings and what size they are. Note that the ruler is in centimeters.
