How many letters of recommendation do I need? Although it can vary, generally, you will be asked for three letters. We recommend that you send only the number of letters requested. Admissions committees do not have enough time to read extra credential.
The most effective letters of recommendation are written by professors or work supervisors who know you well enough to describe your academic, personal, or professional achievements and potential with candor, detail, and objectivity. Letters that compare you to your academic peers are often the most useful. Most schools do not consider general, unreservedly praiseworthy letters helpful.