Example 1
- Mode: one test
- Earned 42, maximum 50
84% (B)
42 / 50 × 100 gives 84%, letter B on the US sketch.
Grade calculator
Percent of a number: percentage of a number. Plain mean: arithmetic mean. Here we add a US letter sketch and a needed-on-final mode. Not a school gradebook.
Percent of a number: percentage of a number. Plain mean: arithmetic mean. Here we add a US letter sketch and a needed-on-final mode. Not a school gradebook.
Result
Enter the fields, then Calculate.
How it works
This grade calculator does three jobs from the numbers you type: percent on one test, a weighted mean of up to four parts, and the percent you need on a final to hit a course target. 42 points out of 50 give 84 percent, because 42 divided by 50 times 100. 18 out of 20 give 90. 9 out of 20 give 45. The letter beside the result is a US sketch: A from 90, B from 80, C from 70, D from 60, otherwise F. That is not the Polish 2 to 6 scale, not a transcript mark, and not a row in a gradebook.
The weighted mean is score times weight, summed, then divided by the sum of the weights you typed. 80 at weight 40 and 90 at weight 60 give 86, because 3200 plus 5400 is 8600, and 8600 divided by 100 is 86. Weights need not sum to 100: 75 at 10 and 85 at 30 give 82.5, because we divide by 40, not by one hundred. A blank score or a blank weight skips the row. A weight of zero adds nothing. Four rows are the form cap, not the cap of a school term.
On a final, the needed percent is the target minus current times the share of the course that is not the final, then divided by the final weight. Current 80, weight 20, target 80 gives 80 on the exam. Current 70, weight 20, target 90 gives 170, so it is impossible with that weight. Current 95, weight 10, target 85 goes negative: you are already there. A final weight of 0 does not divide. This is not Canvas, not PowerSchool, and not a school SIS: we do not store marks and we do not know a lecturer rounding rule.
An empty field computes nothing. A comma and a dot are the same decimal. The metric and US switch does not change the percent. Header currency does not convert 84 into money, because there is no amount here. Percent of a number without a test is on a separate page. A plain arithmetic mean without US letters has its own page too. Extra credit above 100 percent is allowed in test mode when the maximum is positive.
How to use
- Pick a mode: one test, a weighted mean, or the percent needed on the final.
- In test mode type points earned and points possible, then press Calculate.
- For a weighted mean fill a score and a weight in a row; a blank field skips that part.
- For a final enter current average, exam weight, and the course target percent.
- Read the percent and the US letter; it is an A to F sketch, not a Polish 2 to 6 mark.
Formula
percent = earned / maximum × 100
Weighted mean = Σ(score × weight) / Σ(weight). A blank score or a blank weight skips the row. Weights need not sum to 100.
Needed on the final = (target − current × (1 − final weight/100)) / (final weight/100). Above 100: impossible with this weight. Below 0: already there. US letters: A ≥ 90, B ≥ 80, C ≥ 70, D ≥ 60, else F. A sketch, not a 2 to 6 scale.
Examples
Example 2
- Mode: one test
- Earned 18, maximum 20
90% (A)
18 / 20 × 100 gives 90%, the A cutoff from ninety.
Example 3
- Mode: one test
- Earned 9, maximum 20
45% (F)
9 / 20 × 100 gives 45%, under 60 so F.
Example 4
- Mode: weighted mean
- 80 at 40 and 90 at 60
86% (B)
(80×40 + 90×60) / 100 gives 86%, letter B.
Example 5
- Mode: weighted mean
- 75 at 10 and 85 at 30
82.5% (B)
(75×10 + 85×30) / 40 gives 82.5%, weights sum to 40.
Example 6
- Mode: needed on the final
- Current 80, weight 20, target 80
80% (B)
Needed gives 80% on the exam, the same B cutoff.
Example 7
- Mode: needed on the final
- Current 70, weight 20, target 90
170% (impossible)
Needed gives 170%, so a 90 target is impossible at weight 20.
Example 8
- Mode: needed on the final
- Current 95, weight 10, target 85
-5% (already there)
Needed gives -5%, so target 85 is already there at this weight.
Frequently asked questions
Is the A to F letter a Polish transcript mark?
No. It is a US sketch: A from 90, B from 80, C from 70, D from 60, otherwise F. The Polish 2 to 6 scale is not applied, and we do not turn 86% into a four.
Do weighted-mean weights have to add up to 100?
No. We divide by the sum of the weights you typed. 75 at 10 and 85 at 30 give 82.5, because the denominator is 40, not one hundred. A blank weight skips the row.
What if the needed-on-final result is above 100%?
With the weight you typed, the target is impossible. Current 70, weight 20, target 90 gives 170. Raise the final weight or lower the target.
What does a negative needed-on-final result mean?
You already have the target at this weight. Current 95, weight 10, target 85 gives -5. You do not need points on the exam to keep an 85.
Does this save grades into a school SIS or gradebook?
No. We only compute what you type in the form. There is no link to Canvas, PowerSchool, or any electronic class register.
How is Grade calculator different from Percentage of a number?
That page is a% of b, with no letters and no course weights. Here 42 of 50 is a test, plus a weighted mean and a needed-on-final formula. Different context, same ratio in test mode.
Does the metric and US switch change 84% into another figure?
No. A percent stays a percent. The unit switch does not multiply 42 or 50. Header currency also does nothing, because there is no amount here.
Does a comma in the points work the same as a dot?
Yes. 18.5 out of 20 computes. Skip thousand separators with spaces. An empty field computes nothing; zero earned on a positive maximum gives 0%.
Is extra credit above the maximum an error?
Not in test mode. 22 out of 20 gives 110%. The letter still stays at A, because the A cutoff starts at 90. A school may cut extra credit with a rule this form does not have.
What is an 80 exam at 60% weight plus a 90 quiz at 40%?
0.60×80 + 0.40×90 = 48 + 36 = 84. Weights are percents on this card and should sum to 100. 0.6 typed as the weight is 0.6%, not 60%.