Can I extend my single entry tourist visa for Thailand and how long do I have to stay?

and just like that we're done, Good luck Erica (y)

Tourist visas usually have a validity of 3 months and you need to enter in that period, the visa cannot be extended.

You will be stamped in for 60 days when you arrive.

You can apply (once) to stay an extra 30 days at an immigration office whilst in Thailand.

You will need to leave after a total of 90 days.

I think you got something wrong

The single entry Tourist visa is valid for use for 3 months after the issuing date.

It gives you a 60-days stay permit upon entry in Thailand

You can extend your stay exactly one time for a 1900.- THB fee, for 30 more days, on any immigration office

Visa itself is valid for 90 days from the issuing date by The Royal Thai Embassy/Consulate General. You will be stamped for 60 days on entry to Thailand using that visa during valid. 60 days start on the day of arrival, and counting starts the arrival day as day 1.

This 60 days entry stamp is eligible for 30 days tourism extension once except for several nationalities (not eligible for tourism extension countries: Sri Lanka, India, Pakistan, Bangladesh, Iran, Nepal, Togo, Nigeria, and Uganda).

The Thai tourist visa is valid for 3 months from its date of issue.

On arrival into Thailand you will be STAMPED in for 60 days...

AND can get a 30 day Extension of Stay at your local Thai immigration office for 1900 Thai baht. = 90 days stay in Thailand