Short answer: convert each test to a percentage, then either average the percentages or pool the marks, whichever your syllabus uses. For a target, work out the total you need and subtract what you have.
Why Your Average Matters
An average test score shows where you stand across a term, not just on one bad or good day. It helps you decide whether to change how you study, and it feeds into your course grade. The calculation looks simple, but tests often have different totals, some may be dropped and some may count more. This guide takes four tests from raw marks to an average and shows how to work out the score you need next.
Step 1: Convert Every Test to a Percentage
Tests out of different totals cannot be averaged directly, so convert each to a percentage first. If you need a reminder, see our guide on converting a score into a percentage.
| Test | Marks | Percentage |
|---|---|---|
| 1 | 14 out of 20 | 70% |
| 2 | 33 out of 40 | 82.5% |
| 3 | 41 out of 50 | 82% |
| 4 | 18 out of 25 | 72% |
Step 2: Choose the Method
There are two common ways to average, and they give different answers when the totals differ.
- Mean of percentages: every test counts equally. (70 + 82.5 + 82 + 72) ÷ 4 = 306.5 ÷ 4 = 76.63%.
- Pooled marks: bigger tests count more. (14 + 33 + 41 + 18) ÷ (20 + 40 + 50 + 25) = 106 ÷ 135 = 78.52%.
The pooled method gives more weight to the 50-mark test, where you did well, and less to the 20-mark test, where you did worst. Use whichever your syllabus describes. If it says nothing, ask your instructor.
Step-by-Step Example
For the mean-of-percentages method, add the four percentages, 70 + 82.5 + 82 + 72 = 306.5, and divide by the number of tests, 4. The result is 76.625, which rounds to 76.63%. Keep the decimals until the end. If you round each percentage first, small errors can add up, especially with many tests.
Dropping the Lowest Score
Some courses drop the lowest test. Here the lowest is test 1 at 70%. Without it, the average of the other three is (82.5 + 82 + 72) ÷ 3 = 236.5 ÷ 3 = 78.83%, which is 2.2 points higher. Check whether the rule applies to tests only, and whether the lowest is dropped by percentage or by marks, since the answers can differ.
What You Need on the Next Test
Suppose a fifth test is coming, and you want an average of 80% across all five with each test counting equally. The total for five tests must be 5 × 80 = 400. You have 306.5, so the next test must provide 400 − 306.5 = 93.5%. That is possible but demanding. If the answer is above 100%, the target is out of reach with one test, and you should plan across several tests.
Tracking Your Average Through the Term
Update your average after each test and look at the trend. Using the mean of percentages, your average after each test is:
| After test | Running total | Average |
|---|---|---|
| 1 | 70 | 70.00% |
| 2 | 152.5 | 76.25% |
| 3 | 234.5 | 78.17% |
| 4 | 306.5 | 76.63% |
The average rose after test 3 and fell after test 4, because 72% was below the running average. A short run of results is noisy, so judge the direction over several tests, not one.
When Some Tests Count More
If a test counts double, give it double weight. Suppose test 4 counts twice. The weighted average is (70 + 82.5 + 82 + 72 × 2) ÷ 5 = 378.5 ÷ 5 = 75.7%. The five in the denominator is the total weight, not the number of tests. Our guide on how to calculate a weighted average covers this fully.
Your Average Is Not Always Your Grade
An average of tests is only one part of a course grade. Assignments, projects and the final exam usually count too, and each has a weight. Use your test average as a guide, then combine it with the other parts using the method in our guide on calculating your current grade. A strong test average can still give a weak grade if a heavily weighted exam goes badly.
Combining Averages From Two Terms
If you have an average for each term, weight them by the number of tests. Suppose your first term average is 74 from 4 tests and your second is 82 from 6 tests. The combined average is (74 × 4 + 82 × 6) ÷ 10 = (296 + 492) ÷ 10 = 78.8%. A simple average of 74 and 82 would give 78, which ignores that the second term had more tests. Use the number of tests, or the marks, as weights.
How Far One Test Moves Your Average
With four tests and a running total of 306.5, a 90% on the fifth gives (306.5 + 90) ÷ 5 = 79.3%, and a 60% gives (306.5 + 60) ÷ 5 = 73.3%. Each test moves the average by its distance from the current average divided by the number of tests so far. Early in the term one test moves it a lot. Later in the term the same result moves it much less, which is why a poor first test can be recovered.
Setting a Realistic Target
The target formula gives a quick table of what the fifth test would have to deliver:
| Target average | Working | Score needed on test 5 |
|---|---|---|
| 76% | 5 × 76 − 306.5 | 73.5% |
| 78% | 5 × 78 − 306.5 | 83.5% |
| 80% | 5 × 80 − 306.5 | 93.5% |
| 82% | 5 × 82 − 306.5 | 103.5%, not possible |
A target of 82% cannot be reached with one more test, so you would need to plan across several. Choosing a target that the arithmetic allows keeps motivation realistic.
Keeping a Simple Record
A short table is enough. For each test, write the date, the marks, the total, the percentage and the running average. Update it the day a result comes back, while you still remember what went wrong or right, and add a one-line note about the cause. After a few tests the notes show patterns, such as losing marks to timing or to one topic, which are more useful than the average itself. Keep the table with your syllabus so that you can recalculate quickly if the rules change.
Common Mistakes to Avoid
- Averaging raw marks from tests with different totals. Convert to percentages first.
- Using the wrong method. Check whether your syllabus pools marks or averages percentages.
- Forgetting special rules. Look for dropped scores and double-weighted tests.
- Dividing by the wrong count. Use the number of tests or the total weight.
- Rounding early. Keep decimals until the final answer.
Check Your Work With BioScribe
BioScribe’s Average Calculator finds the average of a set of scores. Enter the four test percentages above to check 76.63%, then try your own tests.
Frequently Asked Questions
Should I average percentages or pool the marks?
Use the method in your syllabus. If tests have different totals, the two can give different answers, so ask your instructor when it is not stated.
How do I average tests with different totals?
Convert each test to a percentage first. Then average the percentages, or add all the marks and divide by all the totals.
What if my lowest test is dropped?
Remove it from the list, then average the rest. Check whether the rule drops the lowest percentage or the lowest mark.
How do I find the score I need to reach a target average?
Multiply the target by the number of tests including the next one, then subtract the total you already have.
Is my test average the same as my course grade?
Not usually. A course grade combines tests with assignments and exams using weights, so the test average is only one part.
Conclusion
To find your average test score, convert every test to a percentage, choose the method your syllabus uses, and apply any special rules such as dropping the lowest. Then use the target formula to see what the next test must deliver. Track the average after each test, and remember that it is one part of your overall grade.
