THE NUMORIX GUIDE
How to use the Test Score Calculator
Last reviewed September 14, 2026
What this calculator does
Compute maximum score = total questions * points per question, earned score = correct*points - incorrect*negative marking, then percentage = max(0, earned/max)*100.
Formula and method
Compute maximum score = total questions * points per question, earned score = correct*points - incorrect*negative marking, then percentage = max(0, earned/max)*100. Letter grades use A at 90, B at 80, C at 70, D at 60.
Variables and inputs
Correct defaults to 85, Total to 100, Points per Question to 1, and Negative Marking to 0.25 points for each incorrect answer. Incorrect count is total - correct.
Worked example
For 85 correct out of 100 with 1 point and 0.25 negative marking: incorrect=15; earned=85*1 - 15*0.25 = 81.25; max=100; percentage=81.25%; grade=B.
How to interpret the result
The percentage reflects the scoring rule, including penalties. It is not necessarily the same as correct answers divided by total when negative marking is active.
Common mistakes to avoid
Do not subtract the penalty from every question, and do not use negative marking as a percentage unless the exam explicitly defines it that way.
Assumptions and limitations
The engine does not reject correct counts above total, so enter logically consistent counts. It floors negative earned percentages at zero and uses fixed letter-grade cutoffs.
Practical use and checks
The Test Score Calculator accounts for both correct answers and a penalty for incorrect answers. Enter 85 correct, 100 total, 1 point per question, and negative marking 0.25 as a check. Incorrect answers are 15, earned points are 85 minus 15 times 0.25, or 81.25, so the percentage should be 81.25% and the fixed letter-grade output should be B. Set negative marking to 0 to check an ordinary no-penalty test: the same response count becomes 85%. Use the result to compare scoring rules, not to estimate learning from a percentage alone. Negative marking must be entered in points per wrong answer, not as 25 for 25% unless the exam explicitly defines that unit. Check whether unanswered questions count as incorrect before filling the total. The calculator uses fixed A/B/C/D thresholds of 90, 80, 70, and 60 and does not know a school's custom rubric, partial credit, dropped questions, or bonus points. It also needs logically consistent counts; entering more correct answers than total can produce an arithmetic result that has no test meaning. A negative earned score is floored at zero for the percentage, which is a display rule rather than a universal exam policy. Keep the official scoring instructions beside any result used in a grade appeal.