How Does a Weighted Grade Work? (And How to Calculate Yours)

Most courses don't treat every assignment equally. The final might be worth half your grade while homework is worth a fifth — and if you average your percentages without accounting for that, you'll get the wrong number. Here's how weighted grading works and how to compute your real course grade.

The formula

course grade % = Σ (score × weight) ÷ Σ weight

Each component's average is multiplied by its weight, then everything is summed. When the weights add up to 100 (the usual case), you can just divide by 100.

Worked example

Homework: 92% × 20 · Midterm: 78% × 30 · Final: 85% × 50

weighted sum = 1840 + 2340 + 4250 = 8430 → 8430 ÷ 100 = 84.3%

Notice the final dominates: even though homework was your best category, the 50-weight final pulls the result toward your exam performance. That's the whole point of weighting.

Common mistakes

• Averaging percentages directly — (92 + 78 + 85) ÷ 3 = 85%, which is wrong here because the categories have different weights.
• Using points instead of weights — a 20-point homework category is a 20% weight, not 20 points.
• Weights that don't sum to 100 — usually a sign of a typo; double-check your syllabus.

Weighted vs. total-points courses

Some courses instead add up raw points (a 50-point midterm, a 100-point final). That's the points method, and it's a different calculation — the grade calculator handles it.

Let the Weighted Grade Calculator do the arithmetic, then use the Final Grade Calculator to see what the exam can change.