19 August 2026
UMS Explained: Converting Raw Marks on Legacy A-Level Maths Modules
What UMS means, why an A was always 80/100, and how to convert raw marks on C1-C4, M1, S1 and FP1 papers from Edexcel, AQA and OCR.
UMS Explained: Converting Raw Marks on Legacy A-Level Maths Modules
If you are practising on pre-2017 modular A-Level Maths papers — C1, C2, C3, C4, M1, S1, FP1 — the mark you score out of 75 does not map neatly onto a grade. Those modules were graded on the Uniform Mark Scale.
Why UMS existed
Under the modular system, students sat units in different sessions where papers varied in difficulty. UMS normalised each unit onto a 100-point scale so that:
- A = 80 UMS
- B = 70 UMS
- C = 60 UMS
- D = 50 UMS
- E = 40 UMS
A raw 62/75 might be 80 UMS one year and 78 the next. The grade letter stayed consistent even when the paper did not.
Converting your score
Our free UMS Converter stores the published boundary anchors for the main Edexcel, AQA and OCR modules and interpolates between them, so you get both a UMS score and the grade it corresponds to.
Sitting the current linear A-Level?
The reformed A-Level (Papers 1, 2 and 3) does not use UMS at all — it is graded on raw marks across the whole qualification. For that, use the grade boundary predictor instead.
Whichever spec you are on, the fastest way to move up a grade is timed papers with worked solutions — all available in the MathVault library — and a plan built with the revision timetable generator.