Same weight different, dress size

[SamE1995]

Hi!

In 2021 I weighed 16st 6lbs and was a size 24, I started slimming world and lost 3st 7lbs.

I then met my now boyfriend and got comfortable so I've put it all back on plus a little extra lbs.

I'm now 16st and 11lbs but currently a size 20.. why is my dress size smaller now than what it was back in 2021 when I was a few lbs lighter?

Are you talking about the same dress or just general sizing in the shops? Are you changed where you buy your clothes from? Some brands do vanity sizing.

Whilst it is over a much longer time period - I am 2 stones heavier than I was 30 years ago but in some stores I can wear the same clothing size. It is pretty crazy.

General sizing in shops.
I still have clothes from being a size 24 and they're far too big on me now but I weigh more now.

So a dress you had three years ago was tight and now feels big? Then I have no idea. We do change where we store fat as we age, but such a difference in sizes is a mystery.
I don't need to weight myself or rely on clothes to know I have put/lost weight, I can see it in the mirror. How do you see yourself compared to three years ago?

Could be an error on the scales, either then or now.

Could be that you are carrying it differently- lost it off your bust, gained it around your thighs for example.

You could be more muscular, if you exercise more than you used to.