Cambridge Advanced Nationals are 'unitised qualifications', which means they are designed to be taken in chunks, or units, throughout the course. Marks (and unit grades) are accumulated along the way, and when all the required units have been taken, an overall grade is issued. Since exam papers can vary in difficulty from one series to the next, a common scale is used (called the uniform mark scale or UMS) to make sure marks gained on an easier paper do not advantage candidates compared with those who gain marks on a harder paper. 

For examined units:

1. Students sit the exam and the script is marked by an examiner according to a set of strict criteria. The examiner then calculates the raw mark.
2. An awarding meeting takes place, with a group of experienced senior examiners comparing papers from that year with previous papers and statistics. Using their professional judgement they decide what the grade boundaries should be.
3. The raw marks for the unit are converted to a UMS.

For NEA units:

1. Students complete their work which is marked by their teacher to determine the number of criteria they have achieved for the unit. 
2. The moderation process checks there are no issues identified with the marking of any criteria.
3. The raw marks or number of criteria achieved are converted to a UMS.

Details of the number of criteria and UMS marks available for each unit can be found in section 6.4 (Grading and awarding grades) of the specifications.

The grade of the overall qualification is calculated by adding together the uniform marks achieved in the individual units. This gives candidates a final uniform mark which is compared against the overall UMS grade boundaries. 

Both the unit uniform marks and grades, and the final uniform mark and grade are given on the results slip.