A-Level · 26 September 2026 · 6 min read
Physics marks explained: raw marks, weighting, UMS and grade boundaries
“I got 70%, so what grade is that?” sounds simple, but it leaves out the qualification, paper, series and type of mark. Seventy per cent on one paper may not have the same meaning as seventy per cent of a weighted qualification total or seventy per cent of the available UMS.
This guide explains the calculation choices with invented examples. It does not predict future boundaries. For a real result, use the official document or converter matching the exact code and examination series, and ask your centre to resolve any missing award information.
Start by labelling the number you have
Write the score and its denominator before doing anything else: 56 out of 80 raw marks, for example. Add the paper code, series and whether it was a timed original attempt. A percentage without those labels loses information. An informal worksheet assembled from several sources is useful practice, but it does not necessarily have an official grade boundary.
Raw marks measure the credit awarded on that assessment. They are especially useful for reviewing where marks were lost. A grade summarises performance against an awarding standard; it is not a list of the skills you have mastered. Keep both kinds of information so that a result can guide revision rather than just label it.
Weighting changes contribution, not the answer marked on the page
For Cambridge IGCSE Physics, use the component weightings for your route rather than adding every available raw mark as though all components contributed equally. In the common three-component pattern, theory and practical components have different maximum marks and percentage contributions. The syllabus and grade-threshold document identify the relevant combination.
Consider an illustrative set: 28/40 in a component weighted 30%, 56/80 weighted 50%, and 30/40 weighted 20%. The weighted percentage is 0.30 × 70 + 0.50 × 70 + 0.20 × 75 = 71%. Simply adding raw marks gives 114/160 = 71.25%, a different result. This arithmetic illustrates weighting; use the board’s actual aggregation and thresholds for a real grade.
Linear Edexcel IGCSE uses the qualification total
For Edexcel linear International GCSE Physics 4PH1, the papers contribute to the overall qualification result. Do not use an IAL UMS calculator for this route. A notional boundary for a single paper can be useful feedback, but it is not a separate awarded subject grade or a promise about the final combined result.
When reviewing a completed paper set, match the published subject boundary to the correct series and code. If you mix Paper 1 from one year with Paper 2 from another, you still have useful practice evidence, but no single official series boundary applies cleanly to that hybrid set. Keep the comparison honest instead of forcing a precise grade onto mismatched material.
Modular International GCSE introduces UMS
Edexcel modular International GCSE results use raw marks converted to UMS for unit results and aggregation. That does not make a raw percentage and a UMS percentage interchangeable. The conversion depends on the particular unit and series. Select the modular qualification, not the similarly named linear course, when looking up results information.
Use a three-column record: raw score, official UMS and unit code. Add the overall cash-in result separately. This helps you notice when you have unit results but have not confirmed the qualification award. If a number looks surprising, first check whether you have mixed raw and UMS scales before assuming the marking is wrong.
IAL UMS is not a constant multiplication of raw marks
An invented unit has an 80-mark paper and a 120-UMS maximum. Multiplying every raw mark by 1.5 would convert the maxima, but it does not establish the real conversion for a particular series. Official boundaries and conversion rules determine how raw performance maps onto UMS. Use Pearson’s converter once the relevant series is available.
For the full IAL award, combine the eligible unit UMS according to the qualification rules. A2 performance also matters separately for the A* condition in Physics. Use the dedicated A* guide for that calculation; this page’s purpose is to stop different types of marks being mixed before the calculation begins.
Use boundaries to interpret completed exams, not predict future ones
Historical boundaries tell you about a completed assessment series. They cannot guarantee the raw score needed in an exam that has not yet been awarded. Aiming for exactly last year’s threshold is fragile because the next paper, your performance and the awarding outcome may differ. Prepare for the specification and build a margin through reliable skills.
After marking a paper, record its exact version, error categories and any official grade interpretation. Then choose one correction task. A student who repairs graph gradients, unit conversions and missing explanations has a useful improvement plan; repeatedly checking a boundary without changing the underlying work does not create one.
Questions, explained
Choose a question for a direct answer, then explore the explanation and supporting resources. Each answer has its own link to save or share.
What is the difference between raw marks and UMS?
Raw marks are awarded for answers on an assessment. UMS is a converted scale used for modular qualifications so unit results can contribute consistently across series. The conversion is specific to the qualification, unit and series; it is not necessarily the same percentage or a fixed multiplication.
What grade is 70% in Physics?
It cannot be determined from the percentage alone. You need the qualification, component or overall award, examination series and type of mark. A raw paper percentage, weighted qualification percentage and UMS percentage can have different meanings. Use the exact official boundary or converter.
Does IGCSE Physics use UMS?
Some routes do and others do not. Edexcel modular International GCSE uses UMS; Edexcel linear International GCSE does not use that modular conversion. Cambridge uses its own component weighting and grade-threshold arrangements. Identify the qualification code before choosing a calculator.
Can I average my Physics paper percentages?
Only if that reflects the prescribed contribution of the components. With unequal weightings, use a weighted calculation. Even then, a practice percentage is not a confirmed grade until it is interpreted against the correct official aggregation and boundary information for that examination series.
Can I know next year’s Physics grade boundaries now?
No precise future raw boundary can be guaranteed in advance. Historical boundaries provide context for completed papers, not a fixed target for a future award. Use practice results to identify skill gaps and consult official information when the relevant series is awarded.