The basic formula
((points earned + extra credit) ÷ points possible) × 100For example, 18 points earned out of 20 is 90%. Add 2 extra-credit points and the result becomes 100%. GradCal allows results above 100% because some assignments use uncapped extra credit.
Points off in stack mode
Stack mode begins with the assignment total and subtracts the points you tap. On a 20-point paper, tapping one point off twice and half a point once leaves 17.5 points earned, or 87.5%.
Rounding comes before the letter
The selected rounding rule is applied before GradCal chooses a letter grade. With whole-number rounding, 89.5% becomes 90% and reaches an A on the default scale. With exact grading, it remains below the A boundary.
Default letter-grade scale
- A: 90% and above
- B: 80%–89.99%
- C: 70%–79.99%
- D: 60%–69.99%
- F: below 60%
Schools use different boundaries, so check the written policy before recording final grades. GradCal for iPhone includes custom grading scales.
Decimals and zero totals
You can enter decimals with a period or comma. A total of zero does not produce a percentage because division by zero is undefined. Earned points cannot be negative.
What GradCal stores
A browser session uses only paper numbers, points, percentages, and letter grades. There are no fields for student names, IDs, emails, schools, or class rosters.
Read the grading-scale guide or return to the calculator.