Add each course with its grade and credit hours — the GPA updates live as you go, on whichever scale your school uses.
Each course's grade is converted to grade points on your selected scale, multiplied by that course's credit hours, then all of those are summed and divided by total credit hours — so higher-credit courses count more toward the final GPA.
The 4.0 scale is the most common in the US (A=4.0 down to F=0). The 5.0 scale is typically used for weighted GPAs that give extra credit for honors or AP-level courses. The 10.0 scale is common in India and parts of Europe, often based on percentage marks converted to points.
Yes — each course row has a remove button once there's more than one row, so you can delete any entry and the GPA recalculates immediately.
Grade point values for A-, B+, and similar can vary slightly between institutions (some use 3.7 for A-, others 3.67, for example) — check your school's official grading scale and adjust which grade option you pick accordingly, since small differences can shift a borderline GPA.
Typically no — Pass/Fail courses usually aren't factored into GPA at most institutions, so they shouldn't be added as a row here. Check your school's specific policy, since this does vary.
Worked example: two courses — an A (4.0) worth 4 credits, and a B (3.0) worth 3 credits — give a GPA of (4×4 + 3×3) ÷ (4+3) = (16+9) ÷ 7 = 3.57, not a simple average of 3.5, since credit hours weight the result.