What amount do I need to show in cash at Bangkok airport if asked?

I’ve never been asked in 25 years

20k might get you in but realistically you should stay home if that’s a struggle to prove.

I was asked once at the Rayong border in Myanmar. But I just pulled out my cash. And they didn't count it and were like eh ok fine.

Got be cash if asked

I always bring at least €600 in cash just in case, was asked years ago but it's very rare

No idea never been asked and I live here in and out frequently

IF asked to show amount (very few are asked) it would need to be 20,000 baht or equivalent in cash only. A bank account or credit card statement doesn’t suffice.

Cash amount is incredibly rarely asked for. The law exists that they can ask but they’ll only invoke the rule if they’re looking for a reason to deny you entry. For 99.9% of people that won’t happen.