Add your courses, choose a letter grade or percentage for each one, and calculate your GPA on a 4.0 scale.
GPA is calculated as the sum of quality points divided by the sum of credits.
Letter grades use the 4.0 scale you provided. If you choose percentage, it is converted using this simple scale: A+ = 97-100, A = 93-96, A- = 90-92, B+ = 87-89, B = 83-86, B- = 80-82, C+ = 77-79, C = 73-76, C- = 70-72, D+ = 67-69, D = 63-66, F = below 63.