How to Measure Yourself for Period and LBL Briefs
By Shop Period Underwear | Love Luna Period Underwear | Published: 2026-10-13
Category: Kaufberatung
Measure your hips and waist correctly to choose a period or LBL brief size that seals without squeezing. Use our step-by-step guide and fit checks.
Quick answer
Measure your hips at the fullest point and your natural waist, then use the brand's size chart—not your jeans size. For period and LBL briefs, the hip measurement is the deciding number because the leak-proof layers need to sit close without digging in. If you are between sizes, size up for overnight or heavy flow, and size down only if you prefer a very firm fit and have measured accurately.
Gather what you need before you measure
Use a soft tape measure and wear thin underwear or nothing under your clothes. Stand in front of a mirror so the tape stays level. If you do not have a tape measure, use a piece of string and measure it against a ruler. Write down both your hip and waist numbers in inches or centimeters—whichever the brand's chart uses—and remeasure once to confirm.
How to measure your hips for period pants
Wrap the tape around the fullest part of your hips and bottom, usually about 20 cm (8 inches) below your natural waist. Keep the tape snug but not tight, and parallel to the floor. This is the measurement that determines whether the absorbent panel covers the right area and whether the leg openings seal gently. If you are measuring for LBL briefs, the same hip measurement applies, but pay extra attention to the leg opening if you have sensitive skin.
How to measure your waist and check the rise
Your natural waist is the narrowest part of your torso, often just above the belly button. Measure it relaxed, after breathing out normally. The waistband should sit comfortably without rolling or pressing. For high-waist styles, also measure the distance from your waist to your crotch to see if the rise will sit where you expect. If you have a long torso, a higher rise may fit better; if you are short-waisted, a lower rise can prevent the band from digging under your ribs.
What to do if you are between sizes
Between sizes, the right choice depends on flow and use. For heavy flow, overnight wear, or LBL, size up—the extra room lets the absorbent layers sit flat and reduces leaks at the leg openings. For light flow or daytime wear, you can size down if you prefer a compression-like fit, but never so tight that it leaves red marks. Always check the brand's specific size chart because period underwear sizing is not the same as regular underwear sizing.
Signs your period underwear is too tight
If the waistband leaves deep marks, you feel pressure on your bladder, or the leg openings pinch, the brief is too tight. A too-tight fit can also cause the absorbent panel to bunch, which creates gaps and leaks. Try a size up or a different style with more stretch. Remember that period underwear should feel secure, not restrictive.
Decision rules for period and LBL brief sizing
- If your hips measure between two sizes: Choose the larger size for heavy flow, overnight use, or LBL. Choose the smaller size only for light flow and if you prefer a very snug fit. When in doubt, size up—you can always adjust with a different style.
- If you have a long torso: Look for high-waist or full brief styles that provide more rise. Measure from your natural waist to your crotch to confirm the rise will sit comfortably. A higher rise prevents the waistband from digging into your ribs.
- If you have sensitive skin or bladder sensitivity: Avoid tight leg openings and choose styles with softer edges. Size up if needed to reduce pressure on the bladder. Comfort is key—tightness can cause irritation and leaks.
- If you are buying period swimwear: The same hip measurement applies, but swim fabric has less stretch than cotton. If you are between sizes, size up for swim to avoid restricted movement. Swim briefs should feel secure but allow full range of motion.
Product facts to guide your choice
- Adult Period Swim Bikini Brief - Black: Adult Period Swim Bikini Brief - Black features 4 clever layers of protection and special water-repellent fabric. The water-repellent layer keeps period blood locked in even when swimming, so the fit needs to be snug enough to seal but not so tight that it restricts movement.
- Adult Period Swim Bikini Brief - Deep Pine: Adult Period Swim Bikini Brief - Deep Pine has the same 4-layer protection and water-repellent fabric as the black version. If you prefer a different color, the fit and performance are identical, so you can choose based on style without compromising protection.
- Adult Period Swim Full Brief - Dusk: Adult Period Swim Full Brief - Dusk is a high-waist style with 4 layers of protection and water-repellent fabric. The full brief offers more coverage and a higher rise, which can be more comfortable if you have a longer torso or prefer extra security around the waist.
- Swim Textured Triangle Bikini Top - Electric Blue: Swim Textured Triangle Bikini Top - Electric Blue is designed to match back with Love Luna period swim bottoms and has a water-repellent and chlorine-resistant treatment. Pairing the top with period swim bottoms ensures a coordinated fit, and the chlorine-resistant fabric lasts longer in pools.
Who this sizing method works for
Best for
- Anyone buying their first period or LBL brief who wants to avoid returns
- People who are between sizes and need a clear rule for choosing
- Swimmers who need period swimwear to fit securely without leaking
Not for
- Those who prefer to rely only on dress size without measuring
- People who want a very loose, relaxed fit for light flow
