The standard button size can vary depending on how you’re using them.
2.25″ Button
A standard campaign button size is typically 2.25-inch round, this size is also considered the most popular buttons historically
3″ Button
The Large 3-inch round are often used for photo buttons, this is also one of the most popular buttons people prefer. It is typically used for political campaigns and causes.
1.25″ Button
creative people tend to sell the 1.5-inch round or 1.25-inch round buttons. It is great for artwork and old postcard images and hand drawn images.
1″ Button
The 1-inch round buttons are popular among bands. It is used for merchandise, it is also used by designers, breweries and retailers.