Average Calculator · Practical guide
How to Calculate the Average of Test Scores
The two-step mean for equally weighted tests, and the weighted version when some scores count more.
At a glance
The Two-Step Method
Add all the scores, then divide by how many there are. For test scores of 92, 85, 78, and 88, the sum is 343 and the count is 4, so the average is 343 ÷ 4 = 85.75. Paste the scores into the calculator above with Arithmetic Mean selected and it shows the sum, count, and result in one step.
Interactive tool
Average Calculator
Enter your own values, then compare the result with the examples below.
Result
More Worked Examples
| Scores | Sum | Count | Average |
|---|---|---|---|
| 92, 85, 78, 88 | 343 | 4 | 85.75 |
| 100, 95, 90 | 285 | 3 | 95.00 |
| 72, 68, 81, 74, 90 | 385 | 5 | 77.00 |
| 88, 91, 84, 79, 95, 90 | 527 | 6 | 87.83 |
When Tests Count Differently: Weighted Average
If a final exam counts more than a quiz, a plain average understates or overstates your standing. Multiply each score by its weight and divide by the total weight. A course weighting homework at 20%, a midterm at 30%, and the final at 50%, with scores of 85, 78, and 92, gives (85 × 0.20 + 78 × 0.30 + 92 × 0.50) ÷ 1.00 = 86.4 — higher than the plain average of 85 because the best score carried the most weight.
How One Bad Test Moves the Average
Each test moves the average by the gap between that test and the old average, divided by the new count. Dropping a 60 into the 92, 85, 78, 88 set pulls the mean from 85.75 down to 403 ÷ 5 = 80.6. Conversely, one strong score late in the term moves the average less than an early one, because the count — the denominator — is larger.
Frequently Asked Questions
How do I find what score I need on the next test?
Multiply your target average by the new total number of tests, subtract your current sum, and that is the score required. With an 85.75 average over 4 tests, an 88 on test 5 would keep you at 86.2.
Should I drop the lowest score before averaging?
Only if the course rules say so. Dropping the 78 from 92, 85, 78, 88 raises the average from 85.75 to 88.33, but that is a policy choice, not standard practice.
Does the average change if scores are out of different point totals?
Convert each score to a percentage first, then average. Averaging raw points from a 50-point quiz and a 100-point exam mixes different scales.
Is the average the same as my grade?
Only if every item counts equally. Check the syllabus for weights; if categories differ, use the weighted-average method instead.