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What Grade Do I Need on My Final to Get a B?

Find the exact score you need on your final exam to finish with a B in your course. Note: on a plus/minus scale, 80% might only earn a B−, and a straight B typically sits at 83–86%.

B-Target Calculator

%
Your average so far on graded work
%
Your target course grade (80% = B)
%
What % of your course grade is the final
Required on Final
—
F
0–59 D
60–69 C
70–79 B
80–89 A
90–100

How this is calculated

required = (target − current × (1 − w)) / w

target = grade you want in the course, %
current = your average on graded work so far, %
w = final exam weight, as a decimal (e.g., 35% → 0.35)

Assumption: Your current grade is the average of all work graded so far, which makes up (1 − w) of your course grade. Everything ungraded counts toward the final.

Worked example

You have a 75% average on work worth 65% of the course. Your final is 35%. What do you need to finish with an 80% (B)?

required = (80 − 75 × (1 − 0.35)) / 0.35
required = (80 − 75 × 0.65) / 0.35
required = (80 − 48.75) / 0.35
required = 31.25 / 0.35
required = 89.29%

You'd need an 89.29% on the final. This is achievable but demanding—an A− on the hardest exam of the term.

Understanding B grades: B+, B, and B−

The letter B sounds simple, but schools that use plus/minus modifiers often split it into three bands with different minimum cutoffs. This creates ambiguity when you're aiming for "a B"—you might accidentally target the wrong threshold.

Standard US scales

No plus/minus (five-letter scale): B = 80–89%. Any score from 80% to 89.99% earns the letter B. This is the simplest model and is used by many schools.

Plus/minus scale (13-letter or 12-letter): Schools that use this break B into three bands:

  • B+ = 87–89%: The highest B tier. Often mapped to 3.3 GPA instead of 3.0.
  • B = 83–86%: The straight B. Mapped to 3.0 GPA at most institutions.
  • B− = 80–82%: The lowest B tier. Mapped to 2.7 GPA, borderline between B and C+ in some systems.

Important caveat: These ranges are common but not universal. Some schools use 85–89 for B and 80–84 for B−, or even shift the entire scale. Always check your course syllabus or registrar's handbook for your institution's exact cutoffs.

Why this matters: If you aim for 80% thinking that guarantees a B, but your school uses a plus/minus scale where 80–82% is B−, you've technically earned a B (the letter), but your GPA might reflect only 2.7 points instead of 3.0. Ask your professor or registrar early if this distinction affects your goal.

Required final score by current grade and final weight

This table shows what percentage you need on the final to reach 80% in the course. Every cell is computed live based on the formulas above.

Current Grade Final 10% Final 20% Final 30% Final 40% Final 50%

Frequently asked questions

Is a B the same as 3.0 GPA everywhere?

Not always. A B (3.0 GPA) is standard at most schools, but some use A = 4.0, B = 3.0, C = 2.0, D = 1.0. Others use +/− modifiers, mapping B+ to 3.3, B to 3.0, and B− to 2.7. Check your school's official GPA scale to know how your letter grade converts to GPA points. Our calculator focuses on the percentage cutoff, not GPA—cross-check your institution's conversion table.

Why does my school show a B as 83% and not 80%?

Grading scales vary significantly by school and even by department. Some institutions use 80–89% for a straight B; others split it into B+ (87–89), B (83–86), and B− (80–82). A handful of schools use 85–89 for B. Check your course syllabus or registrar's handbook for your school's exact cutoffs. If uncertain, email your professor to confirm.

Should I aim for 80%, 83%, or 87% to guarantee a B?

Aiming for 83% or higher is the safest bet if your school uses plus/minus grades, because 80–82 might earn only a B−. If your school uses a simpler A/B/C/D/F scale with no modifiers, 80% is the threshold. Use the calculator above and adjust the target field to match your school's exact cutoff.

Can I still get a B if my current grade is below 80%?

Yes, if the final exam is weighted heavily enough. Our calculator shows the exact percentage you need on the final. If that score exceeds 100%, a perfect final won't be enough, and the highest attainable grade is displayed.

Related tools

If you need to explore other grade targets or scenarios, check out:

Sources