Lens Cap Snap

Lens Cap Snap
How do you measure a Camera Lens for a snap-on cap?

Is it the inside diameter of the lens? Should the cap be chosen with a next smaller diameter or eactly the inside diameter? I have several lens which need caps and I don’t want to order them and have them not fit.

Take the measurement of the outside lens diameter. If you have a filter that fits the lens, it denotes the snap-on cap size i.e a 55mm snap-on cap will fit a 55mm filter snugly. Measure the outside lens diameter

MASSA 58mm Snap-On Lens Cap with Strap for Nikon 2 Pcs