What it is
What is a personal statement?
The short answer
A personal statement is the essay UK and Irish universities ask for instead of a statement of purpose. It is subject-led rather than programme-led: it argues why this subject, evidenced by what you have read and done beyond the syllabus. Roughly four fifths of it should be academic, and undergraduate UCAS applications cap it at 4,000 characters.
Subject-led, not programme-led
A statement of purpose argues forward from a research direction and names a department. A personal statement argues from demonstrated engagement with a subject: what you read that was not assigned, what you built or investigated on your own, and what you made of it.
That difference is why converting one into the other is not a matter of trimming words. The three documents compared sets out what actually changes.
Length, and the character count trap
UCAS undergraduate applications allow 4,000 characters, which is closer to 600 words than 800 and forces much harder cutting than applicants expect. Postgraduate personal statements are usually 500 to 1,000 words and set by the university.
Characters include spaces. Paste into the portal and check before the deadline rather than trusting a word processor.
What does not belong in one
The word personal misleads people. Family circumstances, a childhood interest and a general love of learning are not what is being assessed; supercurricular engagement with the subject is.
Where personal circumstances genuinely explain something on your record, place them briefly, as set out in writing about a study gap.
Related questions
How personal should a personal statement be?
Less than the name suggests. UK admissions readers are assessing engagement with the subject, so roughly four fifths of the text should be academic: what you have read beyond the syllabus, what you did with it, and what it made you want to study next.