How this calculator works
This tool computes your current course grade using weighted averages and then
solves backward to find what score you need on the final exam to reach a target course grade.
It also lets you preview (“what if?”) outcomes by changing the final score slider.
Inputs the calculator uses
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Mode A — Category weights: You enter each category’s weight (percent of course)
and your current average in that category. You also enter the final exam weight and a target course grade.
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Mode B — Item list (points-based): You enter rows as
category, earned, possible.
The calculator automatically builds category totals and computes each category’s effective weight from its total possible points.
Items in the “Final” category are treated as the final exam.
Core idea: weighted average
Your course grade is computed by adding each category’s contribution:
a category contributes its weight times its average.
Current grade (without the final)
The calculator first computes the contribution of everything except the final exam:
If you also use the Locked/Completed toggle (Mode A), the tool can show a “so far” average
based only on completed categories. This “so far” value is a renormalized average over the completed weights,
so it reflects your performance on what’s finished rather than treating unfinished categories as zeros.
Predicted grade for a chosen final score
When you pick a final exam score \(F\) (using the slider), the predicted course grade becomes:
This is what powers the live preview in the graphs: moving the final-score slider updates \(F\),
which updates \(G_{\text{pred}}\).
“What do I need on the final?” (reverse-solve)
To reach a target course grade \(G_{\text{target}}\), the calculator solves the same equation for the unknown final score:
Feasibility checks
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If \(F_{\text{req}} > 100\), then reaching the target is not possible with the current grades and weights.
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If \(F_{\text{req}} < 0\), then you have already secured the target (even a zero on the final would still meet it).
Auto-normalizing weights (Mode A)
If you enable Auto-normalize, the calculator rescales all entered weights so they total exactly 100%.
This is useful when instructors publish weights that don’t sum perfectly due to rounding.
If auto-normalize is off, the tool requires that category weights plus the final weight sum to 100% (within a small tolerance).
Mode B weights (points-based)
In Mode B, weights are derived from points:
a category’s effective weight is its share of total possible points. For the final category:
The rest of the calculations follow the same weighted-average and reverse-solve logic as Mode A.
What the graphs show
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Grade target gauge: marks your current grade (without final), your predicted grade (with slider final),
and your target grade, all on a 0–100 scale.
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Predicted grade vs final score: shows the linear relationship between final score and course grade,
with a dashed line for the required final score when a target is set.
