Looking at a dress online and don't know what size to buy

[Palmsun]

I am at a dress online that would be lovely for the summer. I am currently a UK size 20. I don't know if I should buy it in my size or a size down because I am due to start on a new exercise regime with a new piece of exercise equipment ordered.

Wait until summer to order it, or order your correct size.
Having a too small dress in your wardrobe that can’t be worn won’t motivate you to make changes, and weight loss is mostly down to diet. You can always have the dress taken in or wear a belt.

Buy for the size you are now OP.