Hermès HAC & Birkin: The Complete Size Guide
Everything you need to know about the Birkin 40, Birkin 50, Hermès HAC 50, Hermès HAC à Dos, and HAC 40 — sizes, leathers, dimensions, and what sets each one apart.
Birkin 40
The Birkin 40 is the largest of the classic everyday Birkin sizes and the one most associated with serious daily use. At 40 cm wide it comfortably holds a laptop, documents, a wallet, phone, and keys and still has room to spare. Hermès produces it in Togo, Clémence, Epsom, and occasionally exotic skins, with both gold and palladium hardware. Search demand for the Birkin 40 consistently outpaces most other sizes.
Dimensions & Structure
The Birkin 40 measures approximately 40 × 30 × 20 cm. Its base is wider and body deeper than the 35, creating extra carrying capacity. The two rolled top handles are set wide enough to carry comfortably over the shoulder on most body types.
Best Leathers
Togo is the most popular choice: scratch-resistant and shape-retaining. Clémence is softer and more relaxed. Epsom is stiffer and lighter. For a work bag, Epsom or Togo are the practical answers.
Hermès Birkin 40
When people search for the Hermès Birkin 40 with the house name in the query they are usually doing serious research before a purchase decision. The Hermès Birkin 40 prioritises function over the more display-oriented proportions of the 25 or 30. Hermès has periodically signalled that the 40 is being produced in smaller quantities, which has moved collector interest upward.
Hardware: Gold vs. Palladium
The Hermès Birkin 40 comes with gold-plated (GHW) or palladium (PHW) hardware. Gold reads warmer and suits classic neutral leathers. Palladium reads cooler and pairs especially well with greys, blues, and whites.
Authentication Basics
On a genuine Hermès Birkin 40 the saddle stitch is hand-done, slightly angled, and sits recessed into the leather. The blind stamp inside encodes the production year and atelier. Hardware engraving is crisp and deep.
HAC 40
The HAC 40 is where the Haut à Courroies line most directly competes with the Birkin 40 — same width, but the HAC’s characteristic boxy, taller body gives it a noticeably different silhouette. Where the Birkin 40 is rounded and relaxed, the HAC 40 is structured and upright, better suited to longer items and a more formal carry.
HAC 40 vs. Birkin 40
The HAC 40 is taller and boxier than the Birkin 40 and has the leather travel straps on the exterior that are the HAC’s defining feature. The HAC 40’s opening is wider relative to its depth, making it easier to access the full base of the bag.
Colourways & Leathers
The HAC 40 most commonly appears in classic, conservative colourways: black, étoupe, gold, and fauve. Its structured silhouette suits darker, more serious leathers particularly well.
Birkin 50
The Birkin 50 sits at the outer edge of the Birkin range in terms of scale. At 50 cm it functions more like a structured carry-on than a handbag — the Birkin you travel with, not the one you carry to lunch. Hermès produces the Birkin 50 in far smaller numbers than the 30, 35, or 40, making it rarer and more sought after by collectors.
Dimensions & Travel Use
The Birkin 50 measures approximately 50 × 37 × 25 cm. It fits easily in an overhead compartment and its structured base means it does not collapse when placed on its side. Many buyers use it as an alternative to a traditional overnight bag.
Rarity & Value
When examples surface in excellent condition — particularly black Togo with gold hardware — they tend to move quickly. Condition matters especially at this size: heavy travel use shows wear more visibly than on a smaller bag.
Hermès HAC 50
The Hermès HAC 50 is the large-format version of the Haut à Courroies and arguably the most faithful to the bag’s original purpose. Where the Birkin 50 is rounded and somewhat softened, the Hermès HAC 50 is architectural: tall, boxy, with the prominent leather travel straps across the front that define the HAC line.
Structure & Dimensions
The Hermès HAC 50 measures approximately 50 × 36 × 21 cm. Its boxy body means it stands upright on its own — it does not slump when set down even when empty — making it ideal for carrying items that need to stay upright.
Who Buys the HAC 50
The HAC 50 buyer is typically someone who already owns Birkins and is specifically seeking the HAC’s more distinctive silhouette at a large scale. Production numbers are lower than for comparable Birkin sizes, making a specific leather and colour genuinely difficult to find.
Hermès HAC à Dos
The Hermès HAC à Dos is the most modern expression of the Haut à Courroies line: a structured backpack that reinterprets the HAC silhouette for hands-free carry. À Dos means “on the back” in French — and the bag delivers exactly that, with the two signature exterior straps now functioning as the shoulder carry system. It comes in PM and GM sizes.
PM vs. GM: Which Size?
The HAC à Dos PM is the smaller of the two — enough for daily essentials. The GM is larger and functions as a travel or weekend backpack with capacity closer to the HAC 50. Both hold their shape even when worn empty.
Leathers & Styling
Most commonly seen in Togo and Clémence, both of which handle the contact and movement of daily wear well. Classic colourways (black, étoupe, gold) dominate secondary market availability. Hardware is typically palladium.
From the Archive
A selection of HAC Birkin 50 pieces from the 1985 Ligne Ulysse collection — the equestrian heritage that defines the entire HAC line.
Size & Keyword Comparison
| Model | Monthly Searches | Dimensions | Best For | Browse |
|---|---|---|---|---|
| Birkin 40 | 2,200 | 40×30×20 cm | Daily carry, laptop, work | View → |
| Hermès HAC à Dos | 900 | PM & GM | Hands-free backpack | PM / GM |
| Birkin 50 | 700 | 50×37×25 cm | Travel, overnight | View → |
| Hermès HAC 50 | 600 | 50×36×21 cm | Travel, structured | View → |
| Hermès Birkin 40 | 500 | 40×30×20 cm | Daily carry, collector | View → |
| HAC 40 | Emerging | 40×29×18 cm | Structured everyday | View → |
US monthly search volumes. Dimensions vary by production year and leather.
Which One Is Right for You?
Start with how you will actually use the bag. Everyday carry — the Birkin 40 or HAC 40. Travel — the Birkin 50 or Hermès HAC 50. Hands-free — the Hermès HAC à Dos. Use the category links above to explore each size in depth.