For UK passport and Malaysian passport holders, if they arrive in Thailand on a double entry 60day tourist visa, once in Thailand, how long can they extend the tourist visa for?

On the Thai Embassy (UK) website it says they will extend a tourist visa 'not exceeding 60days' but it doesn't actually say specifically how many days will be given

Also how much is the extension? thanks

5. PERIOD OF STAY

Upon arrival, travellers with this type of visa will be permitted to stay in Thailand for a period of not exceeding 30 days or 60 days.

Nationals of countries which are on Thailand’s Tourist Visa Exemption list or have bilateral agreements on visa exemption with Thailand will be permitted to stay for a period of not exceeding 60 days.

• When you enter with a tourist visa you'll be granted a 60 day stay.

You can extend that stay once by 30 days.

The 60 day entry from a tourist visa can be extended for 30 days at an immigration office for a fee of 1900 baht.

Then after that 90 days you will need to leave and re-enter the country to use the 2nd entry of your visa. Be sure you do it on or before the enter before date on your visa.

Tourist visas and "visa exempt entries" can be extended (1900 Bht) at any immigration office.

Tourist visa = 60 days on entry + 30 days extension = 90 days in total

Visa exempt entry = 30 days(at an airport) + 30 days extension = 60 days total

At land borders only those from G7 countries can get a 30 day visa exempt entry all others (if eligible) relieve 15 days.

In a pinch, you can also extend one last time for 7 days after the 30 mentioned above.