How many years are children in secondary school?

[Lumene]

Sorry if this is a silly question but I can’t seem to work it out through google. Is it 6?

This is in UK and assuming they stay all the way through to the end of A levels.

5 years
Yr 7 through to yr 11

That is to GCSE level so age 16

7 if they stay for A Levels
5 if they stay until after G.C.S.Es

Dd did 6 in Scotland, but you can leave after 4.

PP is right to end of GCSEs. To the end of A levels includes years 12 and 13, so 7 years in total.

England -
Year 7 to taking GCSEs in year 11, so 5 years.
Then separately years 12 & 13 for 6th form (A levels, IBDiploma, BTEC L2 or L3, etc)

Scotland 4/5/6 depending

5 years of secondary school followed by 2 years of 6th form or college.

England it is 5 to GCSEs, and then 2 more if they stay in that school for their 6th form. (which they may, or may not do).
In Scotland it is different.

Wales is the same as England on this, so five years to GCSE or seven years if they stay on for sixth form.