Does pre-settled status automatically convert to settled status?
No. And it is very important you renew your status before it expires.
Pre-settled status is limited leave to remain under the EU Settlement Scheme. It allows you to continue living and working in the UK for 5 years, after which it expires.
When you receive your decision email from the Home Office, the PDF attached to the email will explicitly mention which status you have. If you have pre-settled status, it will indicate the day your status expires.
You absolutely must re-apply before your status expires.
If you reach 5 years' residence before it expires, you can apply for settled status before your pre-settled status expires. For example, if you have been in the UK since 2017 and you received pre-settled status in 2019, then if you live continuously in the UK until 2022 you will be able to apply for settled status before your pre-settled status expires in 2024.
It is important not to break your continuity of residence. This means you cannot be out of the UK for more than 6 months in any 12-month period (with one single longer absence up to 12 months allowed for some specific exceptions). Your 5 years’ continuity of residence must have started before 31 December 2020. If you are in any doubt about your absences, use this simple form to answer some YES / NO questions to check your situation: https://t3m-settledstatus-absences.paperform.co/