Cambridge PUM / UMS calculator
Convert a raw mark into a Percentage Uniform Mark on the 0–100 scale. Enter your mark, the total, and the A–E thresholds — get your PUM, grade, and marks to the next band.
Enter the A–E raw-mark thresholds from your official Cambridge grade threshold table for that component. The PUM scale fixes A=80, B=70, C=60, D=50, E=40.
Enter your mark, the total, and at least one boundary to see your PUM.
How the uniform mark scale works
A raw mark on its own doesn't mean the same thing from session to session, because papers vary in difficulty. The uniform mark scale fixes each grade boundary to a set value — A=80, B=70, C=60, D=50, E=40 — and interpolates linearly in between, with full marks at 100 and zero at 0. That way a B is a B whether the raw boundary was 53 or 58. A* (PUM 90) is awarded on the overall subject aggregate, not on a single component, so this component-level tool uses the published A–E thresholds.
New to the term? Read Percentage Uniform Marks explained for the full picture.
FAQ
- What is a Percentage Uniform Mark (PUM)?
- A PUM is a raw mark converted onto a fixed 0–100 scale so grades mean the same thing across sessions and components. The grade thresholds are pinned to set values — A=80, B=70, C=60, D=50, E=40 — with full marks at 100 and zero at 0.
- How do I convert raw marks to UMS / PUM?
- Take your raw mark, the component total, and the A–E raw-mark thresholds for your session. Between two thresholds the scale is linear, so a mark part way through a grade band converts to a PUM part way between the two anchor values. Enter them above and the tool does the interpolation.
- Why is my PUM different from my raw percentage?
- Because the scale is anchored to grade boundaries, not to the raw total. If an A needs 60 out of 75 (80% raw) the A is still pinned to 80 PUM, but a harder paper where an A needs 55/75 (73% raw) also maps to 80 PUM — so your PUM reflects the grade standard, not the raw percentage.
- Is PUM the same as UMS?
- They are the same idea — a uniform mark scale that standardises grades across sessions. UK boards usually call it UMS (often out of a fixed maximum per unit); Cambridge International reports a Percentage Uniform Mark (PUM) on a 0–100 scale. This tool uses the 0–100 PUM model.