What Size Is a Pokémon Card Placeholder?
A Pokémon card is 63 x 88 mm, or 2.5 x 3.5 inches. English and Japanese cards are the same size, so one placeholder size fits every pocket. Every placeholder PDF on this site is drawn at exactly that size, nine to a page, on A4 or US Letter.
Print at 100%
When you print, pick Actual size, 100% or No scaling. "Fit to page" or "Shrink to fit" makes every placeholder a little smaller. Phones and tablets often pick "fit" by default, so check the print settings before you print a big batch.
Check it with a ruler
Print one page and measure a placeholder along its dashed cut lines. It should be 63 mm (2.5 in) wide and 88 mm (3.5 in) tall. If it comes out around 60 mm wide, your printer scaled it: switch to 100% and print again.
Sleeves and binder pockets
Standard sleeves are about 66 x 91 mm and most binder pockets are a little bigger again, so a true-size placeholder slides in like a real card. For a stiffer feel, print on 160 to 200 gsm card stock, or slip the placeholder in front of a bulk common.
How many binder pages?
A 9-pocket page holds nine cards a side. Every page on this site shows how many pages a set, a Pokémon or a Pokédex fills: the National Pokédex fills 114 pages of a 9-pocket binder, and Gen 1 fills 17.