Tattoo sizes
Size decides how much detail a design can hold, not just how much space it takes.
Compare real centimetres on the body before you commit.
Measure the design on your body
Centimetres are more useful than labels such as tiny or medium. Print or draw a rectangle at the proposed dimensions and place it on the body. Check it from a normal viewing distance, since a phone screen makes small designs appear much larger than they are.
More detail requires either more space or more simplification. Small designs need a clear outer shape. Medium work can support secondary texture. Large pieces need a full composition with focal points and deliberate open areas.
Use the 3, 5 and 10 cm references in the size guide as a starting point. The final dimensions should follow the body area and the artist's drawing rather than a fixed category name.
Record both height and width in your notes. A ten centimetre line of script and a ten centimetre circular portrait use very different amounts of skin. Dimensions become meaningful only when they are attached to a shape and placement.
Keep a second size option in your shortlist. If the artist recommends more room for lettering, facial features or wing structure, you can compare the larger version without changing the entire concept during the consultation.