In many countries, it never really does. Only certain portions of it may become sealed from 'public' viewing (e.g.: when you turn 18 your juvenile record is sealed - if you are granted an expungement, that specific crime is sealed). Other than that your criminal record is permanent.
In the UK, it is current policy for criminal records to be stored on the Police National Computer (PNC) until you reach the age of 100, although some details may be stored for longer than that. However, whether you have to declare your criminal record (and whether it will show up on checks) will depend on:
Your adult criminal record is a permanent party of your criminal history. It does not "go away."
Never. Once your busted, it remains as a criminal offence both on your driving record and criminal record.
Criminal offenses do not go away.
Your criminal record is your history of criminal activity. Your history is ALWAYS there and does not "go away" unless it is legally expunged.
IT DOES NOT GO ON YOUR CRIMINAL RECORD
What kind of "record" are you asking about. If it is your driving record - traffic offenses do not "go away" upon your turning 18. They are with you for life. It is only criminal offenses that are "shielded" after you turn 18. If it is a criminal record - go to the Clerk of The Court's Office and advise them that there is a juvenile criminal offense showing on your adult record.
Credit references go away after 7 years. Criminal records never go away.
Civil law suits are not criminal activity. They are a part of you public record, but not your criminal record.
A DUI does not go away. It is a criminal offense and as such stays on the driving record forever.
I'm not familiar with the term "spent," are you asking until it "goes away?" If so - unless the offense was committed prior to your 18th birthday, your criminal record does not "go away" it is ALWAYS with you - forever.
Unless your offense was committed prior to your 18th birthday, you will always have a criminal record - it does not "go away" after a certain number of years.
The remainder of your life. It is a criminal violation and does not go away.