Vintage clothing often appears smaller than modern sizing for several key reasons:

Sizing Standards Have Changed Over Time

Modern sizing has gradually become more generous, a phenomenon called “vanity sizing” — where clothing labeled as a certain size (like a size 8) is actually larger than it used to be, to make consumers feel better about the size they wear.

Different Body Ideals

In earlier decades (especially the 1940s–1970s), the ideal body shape was different — smaller waists, narrower hips, and smaller busts were more typical in pattern designs. Clothes were often tailored to these proportions.

Clothes Were Often Custom-Made or Altered

Vintage garments were frequently sewn at home or tailored to fit a specific person, meaning their sizing doesn’t align with today’s ready-to-wear standards.

Natural Fabric Shrinkage

Older fabrics, especially those not pre-shrunk (like cotton or wool), may have shrunk over time with washing and drying, making them appear even smaller.

Different Labeling Systems

Some countries used different size systems back then, or labeled by bust/waist measurements rather than general sizes like S/M/L or 6/8/10.