The Fit Standard

At BELVYNN, movement is a form of geometry. The activewear industry has long operated on the myth of the universal average — one block, scaled up and down, sold to everyone. We think precision is the alternative, and that it is worth explaining how we get there.

Why most activewear fits badly

Grading a garment is not resizing it. When a brand takes a single pattern and scales it proportionally across a size run, the result fails in predictable ways:

1. Fabric bunching. An inseam that is right for one body puddles at the ankle on another, which ruins the line and creates drag through movement.
2. Waistband migration. A rise that is not calibrated to the torso slips during high-intensity work, or folds over itself at the ribcage.
3. Compression in the wrong place. Support placed by proportion rather than by anatomy does nothing for the muscle it was meant to hold.

Our answer is to cut each style on its own block, and to publish the measurements rather than ask you to trust a letter.

How we grade

Inseam

We set inseam by style and by purpose, not by a single house length.

• 2-Layer Essential Active Shorts — 11cm. Long enough to stay down through a squat, short enough to move.
• Balance 7/8 Mid-Rise — 62cm. Finishes above the ankle, no break, no bunching.
• Unstoppable Full-Length — 67cm. Covered through a deep lunge.

The waistband

Our high-rise bands are double-layered. The upper section is the anchor: a firmer, reinforced band that holds position under load. The lower section is softer, so the diaphragm is free to move. A single-layer elastic does one of those two things well and the other badly.

The hip-to-waist contour

Our patterns are cut with curved seams rather than straight ones, following the musculature of the glutes and lower back. A straight seam has to be pulled into shape by elastic; a curved one sits where it was drawn. That is what holds the shape without a restrictive band.

Flatlock seams

Seams are flatlocked, not overlocked, across our compression pieces. A flatlock joint sits flat against the skin instead of ridging, which is why they are wearable for long sessions without chafing at the inner thigh.

Material: what a high elastane ratio actually does

Most premium activewear runs 15% to 22% elastane. Our four compression bottoms — the Essential Active Compression Shorts, the Balance 7/8, and both Unstoppable Full-Length leggings — are built on a 60% nylon, 40% spandex blend.

Three things follow from that density:

1. Recovery. The fabric returns to shape rather than holding the stretch, which is what prevents baggy knees after a dozen wears.
2. Support. A denser elastane content gives the fabric something to push back with, which reduces muscle vibration through running and high-intensity work.
3. Opacity. A tighter knit holds its coverage under tension, which is what squat-proof actually means.

Our other pieces are built differently because they do different jobs — our bras run 25% spandex for support without compression, our Signature Sculpt leggings 23% polyester-based for a print that will not fade, our tees lighter still for drape. The composition for every piece is listed on its product page, under Fabric & care.

The part most brands will not tell you

Because every style is cut on its own block, our sizes are not consistent across the catalogue. The same body takes a different letter in different styles.

A 72cm waist is an M in our Essential Active Compression Shorts, an S in the Signature Sculpt, and an XS in both the Balance 7/8 and the Unstoppable Full-Length.

That is not an error. A compression short and a full-length legging are doing different work and are cut to different tolerances. But it does mean the letter on the label carries no information on its own — only the measurement does.

So: measure once, then use the fit finder on each product page. Enter one number and it will tell you your size in that specific style, including when you sit between two. If you are between answers, message us and we will tell you.

Our published ranges

Every chart on this site is derived from the manufacturer's flat garment measurements, not estimated from a standard.

Our current range starts and stops where it does because of the production run behind it, not because of who we think our customer is. The next collection extends it in both directions.

Designed in Singapore

Precision is not only measurement; it is also environment. BELVYNN is designed in Singapore and built for heat and humidity. Our fabrics are chosen to move moisture off the skin and spread it across the outer surface, where it evaporates rather than sitting in the garment. A piece that performs in a Singapore August is comfortable anywhere.

Substance over surface

We do not believe in loud logos or fast-fashion cycles. The investment goes into what you cannot see from across a room — the reinforced gusset, the hidden waistband pocket, the brushed interior, the seam that sits flat.

That is the standard. Not a louder claim than anyone else's, but a published one.

Frequently asked

Will 40% spandex feel too tight?

It is firm, and it is meant to be. The fabric settles to your shape within the first few minutes of wear. If you would rather have the support without the squeeze, our Signature Sculpt leggings run lighter, and the fit finder will tell you which size to take in either.

How do I know which size I am?

Measure your waist, bust or chest in centimetres and enter it in the fit finder on the product page. Do not go by the size you take in another BELVYNN style, and do not go by your trouser size.

How do I care for it?

Cold machine wash, hang dry in shade, and no fabric softener. Softener coats elastane and blunts the moisture-wicking, which is the most common way a good legging is ruined. Full care instructions are on each product page.

Do you ship outside Singapore?

Yes — Singapore, Malaysia, Hong Kong and Australia, with delivery dates shown at checkout and free 30-day exchanges in every market.