Semester Grade Calculator: Combine Quarter Grades and Final Exam Weight
Updated 11 April 2026
Most high schools calculate semester grades by combining two quarter grades with a final exam. The most common split is 40% / 40% / 20% (Quarter 1 / Quarter 2 / Final), but your school may use a different breakdown. Enter your grades and weights below to see your semester grade instantly.
Your semester grade:
83.0%
Letter grade: B
How Semester Grades Are Calculated
A semester grade is a weighted average of your quarter grades and final exam. In the most common system, each quarter counts for 40% and the final exam counts for 20%. The formula: Semester Grade = (Q1 x Q1 Weight) + (Q2 x Q2 Weight) + (Final x Final Weight).
Worked Example
Common Semester Weighting Systems
| System | Q1 | Q2 | Midterm | Final |
|---|---|---|---|---|
| Standard (most common) | 40% | 40% | - | 20% |
| With separate midterm | 35% | 35% | 10% | 20% |
| Light final exam | 45% | 45% | - | 10% |
| Heavy final exam | 30% | 30% | - | 40% |
| Trimester system | 33.3% | 33.3% | - | 33.3% |
Check your school's student handbook or ask your teacher which system they use. The calculator above lets you enter any custom weights, so it works for all of these systems.
What You Need on the Final to Save Your Semester
The table below shows what final exam score you need based on your quarter averages, using the standard 40/40/20 weighting. The pre-final average is calculated as (Q1 x 0.40 + Q2 x 0.40) / 0.80, which is the average of your two quarters weighted equally.
| Q1 | Q2 | Pre-Final Avg | For A- (90%) | For B+ (87%) | For B (83%) |
|---|---|---|---|---|---|
| 95% | 90% | 92.5% | 80.0% | 65.0% | 45.0% |
| 90% | 85% | 87.5% | 100.0% | 85.0% | 65.0% |
| 85% | 85% | 85% | 110.0%* | 95.0% | 75.0% |
| 85% | 80% | 82.5% | 120.0%* | 105.0%* | 85.0% |
| 80% | 80% | 80% | 130.0%* | 115.0%* | 95.0% |
| 80% | 75% | 77.5% | 140.0%* | 125.0%* | 105.0%* |
| 75% | 70% | 72.5% | 160.0%* | 145.0%* | 125.0%* |
* Score exceeds 100% and is not achievable without extra credit. Based on 40% / 40% / 20% weighting.
When One Quarter Tanks Your Grade
A bad first quarter is not the end of the world. In a 40/40/20 system, Quarter 1 is worth 40% of your semester grade, which means the remaining 60% (Quarter 2 + Final) is enough to recover significantly. Here are two recovery scenarios:
Scenario: 70% in Q1, aiming for B (83%)
Q1: 70% x 0.40 = 28.0 points
Need: 83 - 28 = 55 points from remaining 60%
Required Q2 + Final average: 55 / 0.60 = 91.7%
Challenging but possible. You need roughly A- performance for the rest of the semester.
Scenario: 65% in Q1, aiming for C (73%)
Q1: 65% x 0.40 = 26.0 points
Need: 73 - 26 = 47 points from remaining 60%
Required Q2 + Final average: 47 / 0.60 = 78.3%
Very achievable. A C+ average for Q2 and the final gets you there.