25

Twenty-five centimetres across the base. In practice: a phone, a compact wallet, keys, a lipstick, and nothing else you had planned to bring.

The 25 has been the most in-demand size for close to a decade, and the gap between what it costs at retail and what it costs on the resale market is wider than for any other size. That premium is driven almost entirely by desirability rather than by scarcity of production.

Who it suits

The 25 works if you carry very little, or if the bag is going out in the evening, or if you are buying primarily for the object rather than the utility. It photographs beautifully and it is genuinely light.

It does not work as a daily bag for most people, and a significant number of buyers who chase a 25 end up carrying a 30. If you are choosing between them and you intend to use the bag properly, be honest about what you carry before paying the premium.

Leather at this size

Structure matters more in a small bag, because there is less mass to hold the shape. Epsom is excellent here — rigid, light, and it keeps the silhouette crisp. Togo works well. Clémence is available but its slouch is more noticeable on a small bag, and Swift softens quickly.

Value

The 25 is the most liquid size in the market: it sells fastest and holds value most reliably, particularly in neutral colours with gold hardware. It is also the size where the premium is most exposed to fashion. Demand for small bags has been extraordinarily strong, and a shift in that would be felt here first and hardest.

That is not a prediction, and nothing here is investment advice — but a buyer paying a large premium for a size rather than for a rarity should understand what they are paying for.