How the calculation works
Each grade is multiplied by its weight. The products are added up and divided by the total of the weights. To find the grade you still need, the same formula is turned around.
Average = (g₁ × w₁ + g₂ × w₂ + …) / (w₁ + w₂ + …)
Needed grade = (target × (W + w) − S) / w
W = total weight so far · S = sum of grade × weight so far · w = weight of the next test.Worked example
Three grades: 7.5 with weight 2, 6.8 with weight 1 and 8 with weight 3. Your target average is 7.5 and the next test has weight 2.
- Sum of grade × weight: 7.5 × 2 + 6.8 × 1 + 8 × 3 = 15 + 6.8 + 24 = 45.8.
- Total weight: 2 + 1 + 3 = 6. Average: 45.8 / 6 = 7.63.
- With the next test the total weight is 8. For an average of 7.5 you need 7.5 × 8 = 60 points in total.
- Needed grade: (60 − 45.8) / 2 = 7.1.
What this calculator does not include
- Rounding rules or pass rules that your school or course uses.
- Tests that must be passed on their own, or a minimum grade for a subject.
- Grades you have not entered. Add all the tests that count.
Amounts are rounded for display only; the calculation itself is not rounded. Results are estimates for information, not financial advice. Last updated: 12 November 2026.
Frequently asked questions
What is a weighted average?
A weighted average gives some grades more influence than others. A final exam with weight 3 counts three times as much as a quiz with weight 1. You multiply each grade by its weight, add those up and divide by the total weight.
What weight should I enter?
Use the weight your school or course gives each test: a percentage such as 40, or a factor such as 2. Only the proportions matter, so 2 and 1 gives the same result as 40 and 20.
How is the grade I need worked out?
The calculator solves for the grade on the next test that brings your new weighted average exactly to your target. If that grade is above the highest possible grade, the target is out of reach with that test.
Does it round my grades?
No. The calculation uses your grades as typed and shows the average to two decimals. Schools round in different ways, so check how yours does it.
Which grade scale does it use?
You can choose 1 to 10, 0 to 10, 0 to 20 or 0 to 100. The scale decides which grades are accepted and what the highest possible grade is.