A bathroom mirror should be smaller than the vanity — specifically 2 to 4 inches narrower on each side — because leaving that visible gap anchors the mirror visually to the vanity rather than making it look like it's floating off the wall or crowding the edges.
The 2-to-4-inch inset rule applies to width; height is a separate calculation based on ceiling clearance and the wall space between the top of the vanity backsplash and any overhead cabinet or ceiling. For a single-sink vanity in the 30–36 inch range, a 24–28 inch wide mirror typically fits this proportion. Over a double vanity (60–72 inches), buyers often choose one wide mirror rather than two smaller ones — in that case, the same inset rule still applies to total width. Xramfy's 5-layer float glass means the reflection stays accurate across the full mirror surface, which matters more as mirror width increases.
- Standard rule: bathroom mirror width should be 2–4 inches narrower than the vanity on each side.
- Single-sink vanities (30–36 inches wide) typically pair with a 24–28 inch wide mirror.
- Double vanities (60–72 inches wide) typically pair with a 48–60 inch wide mirror or two 24–30 inch mirrors.
- Mirror height over a vanity: 5–10 inches of clearance from the top of the backsplash to the mirror bottom is the common install range.
- A 24×36-inch wall mirror is the most common size for a single-sink bathroom; 30×48 or 32×48 suits a double vanity.