The IELTS band score is calculated based on the performance of the test taker in four language skills: Listening, Reading, Writing, and Speaking.
Each of these skills is assessed separately, and a band score ranging from 0 to 9 is given for each. The overall band score is an average of the four individual band scores, rounded up or down to the nearest half or whole band score.
The band score descriptors for each skill level are as follows:
Band 9: Expert user – has full operational command of the language with appropriate, accurate, and fluent communication.
Band 8: Very good user – has a fully operational command of the language with occasional inaccuracies and inappropriate usage.
Band 7: Good user – has an operational command of the language, though with occasional inaccuracies, inappropriate usage, and misunderstandings in some situations.
Band 6: Competent user – has an effective command of the language despite some inaccuracies, inappropriate usage, and misunderstandings. Can use and understand fairly complex language, particularly in familiar situations.
Band 5: Modest user – has a partial command of the language, coping with overall meaning in most situations, though likely to make many mistakes. Should be able to handle basic communication in their own field.
Band 4: Limited user – basic competence is limited to familiar situations. Has frequent problems in understanding and expression.
Band 3: Extremely limited user – conveys and understands only general meaning for in very familiar situations. Frequent breakdowns in communication occur.
Band 2: Intermittent user – no real communication is possible except for the most basic information using isolated words or short formulae in familiar situations and to meet immediate needs. Has great difficulty understanding spoken and written English.
Band 1: Non-user – essentially has no ability to use the language beyond possibly a few isolated words.
Band 0: Did not attempt the test – No assessable information provided.
The band scores are determined by trained and certified examiners who use a detailed scoring system based on specific criteria and descriptors for each skill level. The scores for each section are then averaged to determine the overall band score.