'成功率' (chéng gōng lǜ) literally combines '成' (to succeed), '功' (achievement, success), and '率' (rate, ratio). Together, it means 'success rate' — the proportion of successful outcomes out of a total number of attempts. It’s a quantitative measure widely used in contexts where performance or effectiveness is evaluated objectively, such as medical procedures, engineering tests, educational assessments, or business projects.

This term is neutral in register and appears frequently in formal reports, news articles, scientific writing, and everyday discussions about probability or reliability. Unlike more colloquial expressions like '做得好不好' (how well something is done), '成功率' emphasizes measurable, statistical results — for example, 'the surgery’s success rate is 95%' rather than subjective impressions. It’s often followed by a percentage or fraction and commonly modified by numerals or adjectives like '高' (high) or '低' (low).