Double the score: each question is worth 2 points
100 ÷ 50 = 2, so the percent on a 50-question test is the number right times two: 42 right is 84%, 37 right is 74%. Every score is a whole, even percent, so there is never anything to round, and no teacher's rounding rule can change the grade.
Letter grades out of 50
On the standard scale an A is 45 to 50 right (up to 5 wrong), a B is 40 to 44, a C is 35 to 39, a D is 30 to 34, and 29 or fewer is an F. Each letter spans five or six scores, which is why longer tests sort students more finely than a 20-question quiz.
Plus-minus grades on 50 questions
Because the percents step by 2, each plus or minus letter covers one or two scores: A+ is 49 or 50 right, A is 47 or 48, A− 45 or 46, B+ only 44 (88%), B 42 or 43, B− 40 or 41, C+ only 39, C 37 or 38, C− 35 or 36, D+ only 34, D 32 or 33 and D− 30 or 31.
Example: a 50-question final with 8 wrong
8 wrong is 42 right: 42 × 2 = 84%, a B on both scales. Need the grade that final gives your overall class average? Take the 84% to the final grade calculator. For tests with extra credit or half points, the grading calculator starts at 50 questions; for one score with uneven points, the percentage grade calculator.
Where the letter lines come from
The A–F column uses the standard scale that the School District of Palm Beach County and Roanoke County Public Schools publish: A 90–100, B 80–89, C 70–79, D 60–69, F below 60. The +/− column uses A+ from 97, A from 93 and A− from 90, and so on down to D− at 60. Schools set their own lines, so check your syllabus; the grading scale page compares published scales. Other test lengths: the grading chart for 1 to 100 questions.
50-question grading questions
What is 42 out of 50 as a grade?
42 out of 50 is 84%: double the score, because each question is worth 2 points. That is a B on the standard scale and a B on the plus-minus scale (83 to 86).
How many can you miss on a 50-question test and still get a B?
Ten. 40 out of 50 is 80%, the lowest B (a B− on the plus-minus scale). With 11 wrong the score is 78%, a C.
What is 45 out of 50?
45 out of 50 is 90%, an A on the standard scale and an A− on the plus-minus scale. For an A there, 93% or more, you need 47 out of 50.