Extra credit adds points to your score without adding to the points possible, so your percentage can rise. The effect depends on how much the assignment or course is worth: 15 extra points on a course with 500 points possible lifts an 82% (410/500) to 85% (425/500). Inside a weighted category, the same gain is scaled down by the category’s weight. This guide shows the maths for each case, so that you can see what extra credit is really worth before you spend time on it.

Extra credit is a particular kind of change to a weighted average, so it helps to know the basics. If you want a refresher, read about weighted averages first.

Points-based extra credit

This is the most common type. The teacher offers a number of bonus points, and they are added to your earned points but not to the total possible. Suppose you have 410 out of 500 points, which is 82%. A 15-point extra credit project takes you to 425 out of 500, or 85%. The gain is 15 ÷ 500 × 100 = 3 percentage points.

The value of one point depends on the total. One point on a 500-point course is worth 0.2 percentage points, but one point on a 100-point total is worth a full percentage point. That is why the same bonus helps most early in a course, when few points are possible, and least late in the course. You can check any score with the percentage calculator.

Percentage-based extra credit

Some teachers say “extra credit worth 2%”. That can mean two different things. If it means two percentage points, an 82% becomes 84%. If it means 2% of your grade, then 82 × 1.02 = 83.64%, a gain of only 1.64 points. The difference grows as the percentage grows, so ask which one is meant before you rely on it.

A third version is a bonus on a single test, such as 5 extra points on a 50-point test. A student with 48 out of 50 plus the 5 bonus points would score 53 out of 50, which is 106% on that test. Some teachers allow scores over 100% on one assignment, and others cap the assignment at 100%.

Extra credit in weighted categories

In a weighted gradebook, extra credit first changes the category score, and the category weight then scales the effect on the course grade. Take the 40/20/30/10 example from our weighted guide, where the course grade is 88%. Tests are 40% of the grade, and the student has 164 out of 200 test points, which is 82%.

A 6-point extra credit on the tests raises the category to 170 out of 200, or 85%. That is a 3-point gain in the category, but only 3 × 0.40 = 1.2 points in the course. The grade moves from 88.0% to 89.2%. That is a B+ on the plus/minus scale and still a B on the 10-point scale, because 90% is out of reach. Try your own numbers in the weighted grade calculator.

The lesson is that extra credit in a light category does little. Always multiply the category gain by its weight before deciding whether the work is worth your time.

Caps and limits

Teachers usually limit extra credit so that it cannot rescue a poor term. Common limits include:

• A maximum number of points, such as 5 points over the whole course. On 500 points possible, 5 points is worth only 1.0 percentage point.
• A percentage cap, such as extra credit can add no more than 2% to the final grade.
• A ceiling on the grade itself, such as no course grade above 100%.
• Extra credit only on certain assignments, not on tests.

Read the syllabus before you start, because a cap can turn a big extra credit task into a small gain.

Extra credit and the final exam

Extra credit on a final exam can make a target possible that the exam alone could not reach. A student with 88% and a final worth 30% who wants 93% needs (93 − 88 × 0.70) ÷ 0.30 = 104.67% on the final. If the final has 5 bonus points, a score of 105% gets there: 88 × 0.70 + 105 × 0.30 = 93.1%. Use the final grade calculator to find the score you need, and our guide to how to calculate your final grade for the full method.

Borderline grades

Extra credit matters most when you are close to a cut-off. A student on 447 out of 500 has 89.4%. One extra credit point gives 448 out of 500, or 89.6%. If the teacher rounds to the nearest whole number, 89.6% becomes 90% and the grade changes from a B to an A on the 10-point scale, while 89.4% would stay at 89%. Whether this happens depends on your teacher’s rounding rules, so check them before you ask.

How to ask your teacher

1. Ask early. Extra credit is worth most, and is most often allowed, before the final weeks.
2. Be specific. Ask what the assignment is, how many points it is worth and where the points are added.
3. Ask about the cap. Find out how much extra credit is allowed in total.
4. Ask how it is counted. Is it points added to a category, or percentage points added to the course?
5. Do the regular work first. Teachers rarely give extra credit to students who have missing assignments.

A polite, specific request works much better than asking “can I do anything to raise my grade?”. Show that you have done the maths and know how close you are.

Frequently asked questions