YSL LouLou Bag Size Guide: Toy, Small, Medium and Large Dimensions

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The Saint Laurent LouLou is published in four classic tiers — Toy 20 x 14 x 7.5 cm, Small 25 x 17 x 9 cm, Medium 32 x 22 x 12 cm and Large 38 x 27 x 14 cm — plus a Puffer family and a 2025 lambskin/suede line whose Small measures 24 x 14 x 6 cm. The word Small covers bodies from 20 cm to 26 cm depending on which line and year you are reading, so the measurements matter more than the tier name.

The Saint Laurent LouLou is the house’s padded, Y-quilted shoulder bag, and it has a sizing problem that has nothing to do with the shapes of the bags: the same tier word is used across three different families — the classic Y-quilted line, the Puffer line, and a 2025 lambskin and suede line — and the bodies behind those words are not the same size.

Everything on this page is taken from product pages we read directly: Saint Laurent’s own listings for the Toy, Small, Medium, Large and both Puffer sizes, read through archive snapshots because the live site blocks automated requests, cross-checked against Mytheresa, Saks Fifth Avenue, Neiman Marcus, Rebag and Ann’s Fabulous Finds. Where those sources disagree with each other or with themselves, we say so and keep both numbers instead of averaging them.

Ten tier names, and the four bodies that share the word Small

Chanel-style numbering this is not. Saint Laurent names the classic line by size word — Toy, Small, Medium, Large — with separate style IDs for each: 630951DV7061000 for the Toy, 494699 for the Small, 574946DV7272346 for the Medium and 574947DV7271000 for the Large. The Puffer branch gets its own names, louLou puffer small and louLou puffer medium in quilted lambskin. Then in 2025 the retailers’ listings introduced a lambskin and suede Loulou Small and Medium that do not match the classic bodies at all.

The result is that “Small” can mean four different widths depending on what you are reading:

That is a 3 cm spread inside one tier word, which is wider than the gap between the classic Toy and the smallest Small. Two practical consequences: never compare two LouLou listings by the tier word, and always ask which line a listing belongs to before quoting a size. Our own Saint Laurent LouLou model reference uses the 23 cm figure the brand published for the Small chain bag, and the full table below shows both.

Every LouLou tier measured: cm, inches and both strap drops

This is the complete set of published figures we could source, split by line because the lines differ in their actual measurements. The two drop columns are the two carries the strap allows: shortened (doubled or folded) for shoulder wear, and full length for cross-body.

Notes on reading it:

• The classic Small’s own pages disagree on width. Saint Laurent published 25 x 17 x 9 cm in 2021 and 23 x 17 x 9 cm in 2023 while printing the identical inch line, 9.8 x 6.6 x 3.5 in, in both. Both values are on file in our sources; we lead with 25 cm and flag 23 cm rather than splitting them.
• The 2025 line’s depth is the tell. Its Small is 6 cm deep and its Medium 8 cm, against 9 cm and 12 cm for the classic bodies with the same names. Measuring depth alone tells you which line a bag belongs to.
• Rebag’s per-item measurements run smaller than the brand’s nominal figures — 9 in across for a Small against a nominal 25 cm, 11.5 in for a Medium against 32 cm. Those are measurements of individual pieces, so we treat them as evidence about the tier’s existence and its drops, not as replacements for the published numbers.

Y-quilt, chevron or diamond: sorting the LouLou quilting names

Three words get used for the LouLou’s surface and they describe the same thing. Saint Laurent’s Medium page says “Y-quilted overstitching”; Mytheresa calls the Toy “chevron matelassé quilting”; Rebag files the product name as “Matelasse Chevron”. All three refer to the interlaced V-shaped stitching that gives the Y-quilt its name, and the Y shape comes from the same motif as the logo — the quilting and the YSL monogram are one design idea.

Where it matters: diamond quilting does not appear anywhere in the LouLou sources we read, and the Kate line uses a grain de poudre embossed leather with no quilting at all. So a flat, unquilted or diamond-quilted flap is a different Saint Laurent bag, and the LouLou Puffer is a separate construction again — Saint Laurent’s own product name for it is simply “quilted lambskin”, a puffier quilt than the Y-quilted classic.

The other quilted Saint Laurent shape buyers mix up with the LouLou is the Envelope, which is also chevron-quilted and carries the same monogram. In our own catalogue notes the two are separated by the flap rather than the quilting: the Envelope has a square flap with a chevron V pattern, while the LouLou’s Y-quilt channels open out from the centred monogram on a faceted flap. Ask for a straight-on photo of the flap if a listing only shows the quilting.

The Toy’s wristlet strap and why the drop figures differ by tier

The strap is what changes most across the LouLou range, and it changes in ways the tier names hide.

The classic Toy is the odd one out. Saint Laurent’s page says its “convertible strap can be partially detached and turned into a wristlet”, and it is the only tier that publishes a handle drop — 14 cm — alongside its 57 cm shoulder strap drop. So the Toy is a bag you can carry short on the wrist or long on the shoulder, which is why it reads as a bracelet in some listing photos and a shoulder bag in others.

From the classic Small upward the strap is a metal chain. The Small’s page states the “metal chain strap can be doubled”; the Medium’s page adds that it is a leather-and-metal chain that can be worn doubled on the shoulder; the Large’s page says the strap “can be shortened or worn on the shoulder”. The 2025 lambskin and suede line is described differently again by its retailers — Saks writes “sliding chain strap”, Neiman Marcus writes “sliding chain and leather shoulder strap can be worn single or doubled”, which points to a chain you can move through the grommets rather than one you simply loop.

One figure worth knowing because it looks wrong: the classic Small publishes a 30 cm doubled drop against a 56 cm single drop. Doubling a 56 cm strap should give about 28 cm, not 30, so the two numbers come from different measurement conventions rather than from the same tape. Read both as approximate.

What each tier carries, from a phone in the Mini to a working bag in the Large

Saint Laurent publishes its interiors, which makes capacity easier to reason about than dimensions alone. The Toy has “central flat pocket, 1 zip pocket, 3 card slots”; the Small has “central inside compartment with zip closure, one slot pocket”; the Medium has “two main compartments separated by a zip pocket, one zip pocket”. Every classic tier and both Puffers are grosgrain lined, and the closure across the range is a magnetic snap on the flap.

Depth, not width, decides the last row. The classic Medium is 12 cm deep and the classic Large 14 cm, while the 2025 Medium is 8 cm — a bigger practical difference than the 3 cm between their widths.

The two tiers most buyers end up weighing are the classic Small at 25 × 17 × 9 cm and the classic Medium at 32 × 22 × 12 cm, and the pair is written out on its own page: the Saint Laurent LouLou small vs medium comparison takes the same two rows, adds the 2025 and Puffer figures as separate lines rather than substitutes, and works through which one carries a working day.

The Puffer line: the same model name and two to three centimetres more depth

The Puffer is a different bag wearing the same name. Saint Laurent’s pages call it louLou puffer small and louLou puffer medium in quilted lambskin, and the numbers show why it deserves its own line: the Puffer Small is 29 x 17 x 11 cm against the classic Small’s 25 x 17 x 9 cm, and the Puffer Medium is 35 x 23 x 13.5 cm against the classic Medium’s 32 x 22 x 12 cm. Same heights, two to four centimetres more width, and about two centimetres more depth at each tier.

The straps differ too: both Puffers publish a 28 cm folded drop, where the classic Small doubles to 30 cm and the classic Medium to 26 cm. So a Puffer slouches lower on the shoulder than a classic LouLou of comparable size. If you are comparing a photo of a Puffer with a photo of a classic LouLou, the quilted surface is the giveaway — the Puffer’s quilting is puffier and the body softer, while the classic keeps the defined Y-quilt channels through the YSL monogram.

The 2025 lambskin and suede line is not the classic Small and Medium

This is the trap that catches buyers most often. Saks lists a Saint Laurent Loulou Small Shoulder Bag in Lambskin Leather at 24 x 14 x 6 cm and a Medium at 29 x 17 x 8 cm; Mytheresa lists suede versions at 26 x 14.5 x 6 cm and 30 x 17 x 8.5 cm. None of those four figures matches the classic Small (25 x 17 x 9 cm) or the classic Medium (32 x 22 x 12 cm).

Both 2025 bodies are noticeably shorter and thinner than the classic tiers with the same name. Saint Laurent’s own Medium page gives the classic body a 12 cm depth; the 2025 Saks Medium gives 8 cm. Materials differ too: the classic line is matelassé “Y” calfskin, the 2025 Saks pages specify 90% lambskin leather and 10% brass, and Mytheresa’s are lamb leather suede — a surface that photographs flatter than the Y-quilt and shows marks differently.

If a listing says LouLou Medium and quotes 29 x 17 x 8 cm, it is a 2025-line bag, not a smaller version of the classic. That is not a defect, but it does mean the bag in your hand will be 4 cm thinner than the tier name suggests.

LouLou against the Kate: the flatter envelope shape in numbers

The two are opposite constructions. The LouLou is padded and rounded; the Kate is flat, embossed and precise. Official figures put the gap in the depth column every time:

At the smallest sizes the two are almost the same bag by width — 20 cm against 20 cm — and completely different by depth. The Kate line tops out at the Kate 99’s 26 x 13.5 x 4.5 cm, so there is no flat envelope Saint Laurent offers at the LouLou Large’s size. If capacity is the priority, the LouLou wins at every tier; if you want the bag to lie flat against the body, nothing in the LouLou range does that.

Hardware finishes across the range, and what they do to a photo

The LouLou has been issued in most of the house’s metal tones, and the tier pages show the spread: bronze-toned metal on the classic Medium and Large, oxidized nickel on the 2021 Toy, black metal on the 2021 Small, matte black on the Puffer Small, brushed silver on the Puffer Medium, gold-tone on the Toy listings that Mytheresa carries, and silver-toned on one of the Saks Medium pages. Rebag’s Medium listing uses aged gold.

None of that changes a single measurement. It does change how a listing photograph reads: a black-metal or matte-black lock disappears into black leather, so the bag photographs as an unbroken quilted rectangle and can look larger than it is; a bronze or gold-tone lock marks the centre of the flap and gives the eye a scale reference. When two photos of the same tier seem to show different-sized bags, compare the lock before the measurements.

Three tape measurements that separate the LouLou tiers

If the bag is in front of you, three numbers do almost all the work:

1. Depth at the base. The classic Small is 9 cm, the classic Medium 12 cm, the classic Large 14 cm, the 2025 line 6 and 8 cm. No other single figure separates the classic line from the 2025 line as cleanly.
2. Width across the base, flap closed. 20 cm is the Toy and the retailer-listed Mini is smaller again at 19.5 cm; 23 to 26 cm is a Small depending on line; 29 to 32 cm is a Medium depending on line.
3. Strap drop, measured full length and shortened. A classic Small gives roughly 56 cm long and 30 cm doubled; a classic Medium and the classic Large give 48 cm long; both Puffers give 28 cm folded. A drop outside those bands means a strap has been altered or the bag is from a different line.

Why reading “Loulou Large” on a retailer page can mean the Medium

Retailer naming drifts, and there is a documented case in the sources for this page. Neiman Marcus listed a bag named “Loulou Large YSL Chain Shoulder Bag in Quilted Leather” at approximately 12.6 in wide, 8.7 in high and 3.9 in deep — the classic Medium’s body — while its own 2024 page for “Loulou Large YSL Shoulder Bag in Quilted Leather” gave 14.9 in wide, 10.6 in high and 5.5 in deep, which is the classic Large. The same retailer used one name for two different bodies a year apart.

The same thing happens in reverse with the smallest tier: Saint Laurent names the 20 x 14 x 7.5 cm body the Toy, and no Baby tier appears anywhere in its archived LouLou listings, while a retailer lists a separate Loulou Mini at 19.5 x 12 x 4.5 cm — 2 cm shallower than the Toy and not the same bag.

The fix is always the same three numbers. Send the width, height and depth you want, or the style ID if you have one — 494699 for the classic Small and 574946DV7272346 for the classic Medium are the two we see most — and we will confirm which body a current photo shows before you commit. Browse the Saint Laurent gallery for current photos, or open the Bags Catalog to see every brand album. Tell us the tier and the line on WhatsApp and we will photograph the tier you are considering against a tape.

Both published LouLou Small widths from this page, 25 cm and 23 cm, are separate rows in the Luxury Bag Size Index, so neither figure is quietly dropped.