Sizing for different brands

[JamesSwim]

It's best to try on a suit in a store, but many of us buy mail order. I find that sizes vary a lot.

Are some brands consistently cut small or large compared to your waist size? Or are they different depending on each style they make?

Each maker has a a sizing guide on their web site, but even if you follow it, the fit is different.

Speedo or Nike web sites sometimes say "measure around hips", and others says "measure an inch below natural waist", or (Tyr writes) "measure around natural waist (navel)"

Some web sites like Swimoutlet have ratings "x% says true to size", but answers vary.

Agonswim has it clear -- they have a table for each style they make based on the waist girth and how tight the fit along with % stretch with a web site calculator.

Anyone have a list or rule of thumb on how different brands fit?