How to Calculate GPA — Complete Step-by-Step Guide

GPA (Grade Point Average) is the standard way schools and universities summarize your academic performance into a single number — and it is one of the first things employers, scholarship committees, and graduate programs look at. Yet many students are never actually taught how the number is calculated. This guide walks through exactly how to calculate GPA, step by step, with a full worked example.

Step 1: Convert Letter Grades to Grade Points

Most universities use a 4.0 scale: A = 4.0, A− = 3.7, B+ = 3.3, B = 3.0, B− = 2.7, C+ = 2.3, C = 2.0, C− = 1.7, D+ = 1.3, D = 1.0, F = 0.0. Every letter grade you received in a course converts to one of these point values.

Step 2: Multiply Each Grade by Its Credit Hours

Not all courses are weighted equally — a 3-credit course counts three times as much toward your GPA as a 1-credit course. Multiply each course's grade points by its number of credit hours to get that course's "quality points".

Step 3: Sum and Divide

GPA = (Total Quality Points) ÷ (Total Credit Hours). Add up all the quality points from every course, then divide by the total number of credit hours attempted.

Worked Example

A student took 5 courses in a semester: A (3 credits), B+ (3 credits), A− (2 credits), B (3 credits), A (1 credit). Quality points: (4.0×3) + (3.3×3) + (3.7×2) + (3.0×3) + (4.0×1) = 12 + 9.9 + 7.4 + 9 + 4 = 42.3. Total credits: 3+3+2+3+1 = 12. GPA = 42.3 ÷ 12 = 3.53.

GPA vs CGPA — What Is the Difference?

GPA (Grade Point Average) typically refers to your average for a single semester or term. CGPA (Cumulative GPA) is the same calculation applied across every semester you have completed so far — every course and every credit hour from your entire academic record so far, not just the current term. To calculate CGPA, use the same formula but include every course from every semester.

Updating Your CGPA Each Semester

Rather than re-adding every course from scratch, you can update your cumulative GPA using: New CGPA = ((Old CGPA × Old Total Credits) + (This Semester's GPA × This Semester's Credits)) ÷ (Old Total Credits + This Semester's Credits). This lets you track your running CGPA each semester without recalculating your entire history.

Common GPA Calculation Mistakes

• •Forgetting to weight by credit hours: a simple average of letter grades (ignoring credits) gives the wrong answer whenever courses have different credit values.
• •Including audited or withdrawn courses: these typically do not count toward GPA — check your institution's specific policy.
• •Mixing up GPA and CGPA: make sure you know which one is being asked for, since a single strong semester can look very different from your full cumulative record.
• •Using the wrong grade scale: some institutions use a 5.0 weighted scale (for Honors/AP courses) instead of the standard unweighted 4.0 scale — confirm which your institution uses.