Enter your graded items and their weights to get your weighted course average — with the letter grade included.
What Is a Weighted Grade Calculator?
A weighted grade combines scores that count unequally: a final exam worth 40% moves the course grade more than a quiz worth 10%. The maths: multiply each score by its weight, add them up, and divide by the total weight. With 85 (30%), 92 (40%) and 78 (30%): (85×30 + 92×40 + 78×30) ÷ 100 = 85.70% — a B. This is how almost every course grade on earth is computed, and it is why a bad exam hurts more than a bad homework.
How to Use the Weighted Grade Calculator
- Enter each score as a percentage.
- Enter its weight as a percentage (they do not need to sum to 100 — the tool normalises).
- Click “Calculate Weighted Grade”.
- Read your weighted average with its letter grade.
Formula
Weighted grade = Σ(score × weight) ÷ Σ(weights). Letter scale: A ≥ 90, B ≥ 80, C ≥ 70, D ≥ 60, F < 60.
Worked Example
85 with weight 30, 92 with weight 40, 78 with weight 30: (2,550 + 3,680 + 2,340) ÷ 100 = 85.70% — a B.
How It Works, In Plain Words
Start with the idea that not every piece of coursework counts equally. The What Is section puts it plainly: a final exam worth 40% moves the course grade more than a quiz worth 10%, because each score is multiplied by its weight before anything is averaged. The tool has three rows, and each row takes two numbers: a score as a percentage, and the weight that score carries in the course. Step one is the multiplication: in the worked example, 85 × 30 = 2,550, 92 × 40 = 3,680 and 78 × 30 = 2,340. Step two adds those products: 2,550 + 3,680 + 2,340 = 8,570. Step three divides by the total weight, 30 + 40 + 30 = 100, giving 85.70%. Because the division uses the total weight actually entered, weights that do not sum to 100 are normalised automatically — the same proportions give the same answer. Finally, the percentage is matched against the letter scale from the Formula section — A at 90 and above, B at 80, C at 70, D at 60, F below 60 — so 85.70% comes out as a B.
Real-World Uses
First scenario: a student checking a course grade before results day. The syllabus weights are known and the scores are in, so they enter the three rows and see the course standing at 85.70% — a B — instead of guessing from a plain average. Second: the same student planning the final push. The 40% row carries the most weight, and the What Is section explains why a bad exam hurts more than a bad homework — so revision time goes to the exam rather than to polishing a piece that is already scoring 92. Third: a teacher or tutor sense-checking a gradebook. Entering the published scores and weights confirms the weighted figure matches the one the course records show, and the letter confirms the band. In each case the value is the weighting: the answer reflects how the course actually counts, not a flat mean of the scores.
Benefits
- The exact method courses use, not an estimate
- Weights auto-normalise if they do not sum to 100
- Letter grade included
- Shows why the exam weight matters most
Features of Our Tool
- Instant results in your browser
- No sign-up, no download, 100% free
- Works on mobile, tablet and desktop
- Clear step-by-step explanation below the tool
- Private — your entries never leave your device
Common Mistakes
- Averaging scores without weights — the unweighted mean here would be 85.00, close but wrong in general
- Entering weights as decimals (0.3) and percentages (30) mixed — stick to one
- Forgetting a category: every graded item must be in the weights
Common Mistakes to Avoid
The subtlest trap sits inside the page’s own example: the unweighted mean of 85, 92 and 78 is 85.00, only 0.70 below the weighted 85.70 — close enough to look right while being wrong, and with less even weights the gap can be far bigger. Judge the result against the weighted method, not the flat average. Next, check the weights against the syllabus before trusting the answer: entering 40 on the wrong row swaps which score dominates, and the tool cannot know you transposed them. A blank box stops the calculation with ‘Please enter scores and weights.’, and a negative weight draws ‘Weights cannot be negative.’ — both messages mean an entry needs fixing, not that the tool has failed. Finally, remember the letter comes from this page’s standard 90/80/70/60 scale; if your institution bands grades differently, read the percentage and apply your own scale to it.
FAQ
How do I calculate my weighted grade?
Multiply each score by its weight, add the results, divide by total weight — e.g. 85(30) + 92(40) + 78(30) gives 85.70%.
What if my weights don’t add to 100?
The tool normalises automatically, so any consistent weights work.
What letter grade is 85.70%?
B (on the standard 90/80/70/60 scale).
Why is my grade lower than my best score?
Because lower-weighted scores still pull the average — especially a low score on a high-weight exam.
Is this the same as GPA?
No — GPA averages course grade points over credits; this computes one course’s grade from its components.
Why is the answer not the simple average of 85, 92 and 78?
Because the scores carry different weights. The simple average adds the three scores and divides by three, giving 85.00 — the figure the mistakes list calls close but wrong. The weighted method multiplies first: 92 sits on the largest weight, 40, so it pulls the result up to 85.70%.
What does the tool do if I leave a box empty or enter a negative weight?
It stops and tells you what to fix. Any empty score or weight box brings up ‘Please enter scores and weights.’, a negative weight brings up ‘Weights cannot be negative.’, and if the weights add to zero the message is ‘Total weight must be above zero.’ Correct the entry and calculate again.