What size sanitary pad do you actually need?

Sanitary pads are sized by length, typically Regular (220–250mm) for light flow, Large (250–280mm) for medium flow, XL (280–300mm) for heavy flow or daytime coverage, and XXL/Overnight (300mm and above) for heavy flow or overnight use. Match the size to your flow and the time you'll go between changes — not just to "how heavy" your period generally is.

Quick facts

• Sizing is measured in length (mm), not absorbency volume directly, though longer pads generally also carry more absorbent core

• Regular (220–250mm): light flow days, spotting, or the tail end of a cycle

• Large (250–280mm): medium flow, everyday daytime use

• XL (280–300mm): heavier flow, longer stretches between changes, active days

• XXL/Overnight (300mm+): heaviest flow days or overnight use, with extra back coverage designed for lying down rather than sitting or standing

• Wings add width, not length — a pad's wing size affects how securely it stays in place, separate from the length-based flow rating

Size chart

Note: exact millimetre ranges vary slightly by brand — always check the specific product's stated length rather than relying on the size name alone, since "Large" from one brand can overlap with "XL" from another.

How to actually pick, beyond the label

The size names (Regular, Large, XL, XXL) aren't standardised across the industry the way clothing sizes loosely are — one brand's XL might measure close to another brand's Large. The more reliable way to choose is by two questions: how heavy is your flow on that specific day (not your period overall — flow typically varies day to day within a single cycle), and how long will it realistically be before you can change the pad.

Most periods follow a pattern where the first one to three days are heaviest, tapering off toward the end. That means a single cycle often calls for more than one pad size — heavier-coverage pads (XL or XXL) for the early heavy days, stepping down to Regular or Large as flow lightens. Overnight is a separate consideration from daytime heaviness: lying down changes where flow pools compared with sitting or standing, which is why XXL/overnight pads are typically built with extra length toward the back rather than just more absorbent core throughout.

Fit matters as much as raw size. A pad that's too large for your underwear can bunch or shift, which paradoxically increases leak risk rather than preventing it — sizing up isn't automatically "safer" if the fit becomes unstable. If you're leaking despite using what should be an adequately-sized pad, the more common culprits are wear time (see how often you should change a pad) or placement rather than needing to size up again.