Grades & GPA Reference
The scales and formulas our grade calculators apply: percentage to letter grade, the 4.0 grade-point scale, UK degree classifications, how weighting changes an average, and the formula that answers "what do I need on the final?". Scales vary by institution — yours is the authority.
Grading scales
Three different systems answer "what grade is this?", and they do not agree with each other. These are the conventions our tools use.
Percentage to letter
US convention- A+ / A / A− — 97 / 93 / 90 and above
- B+ / B / B− — 87 / 83 / 80
- C+ / C / C− — 77 / 73 / 70
- D+ / D / D− — 67 / 63 / 60
- F — below 60
A plus/minus scale. Many institutions use whole letters only, or shift every boundary — check your handbook.
Open the Grade Calculator →Grade points
4.0 scale- A / A− — 4.0 / 3.7
- B+ / B / B− — 3.3 / 3.0 / 2.7
- C+ / C / C− — 2.3 / 2.0 / 1.7
- D+ / D — 1.3 / 1.0
- F — 0.0
The unweighted 4.0 scale. Weighted scales let honours and AP courses exceed 4.0, which is why two GPAs are not always comparable.
Open the GPA Calculator →UK degree classification
percentage- First (1st) — 70% and above
- Upper second (2:1) — 60–69%
- Lower second (2:2) — 50–59%
- Third (3rd) — 40–49%
- Fail — below 40%
A UK 70% is a first-class mark, not a C. Comparing UK percentages to a US scale directly is meaningless.
Open the Grade Calculator →Averages & weighting
Weighting is what makes grade arithmetic counter-intuitive. A straight average of your marks is almost always the wrong number.
Weighted average
percentage- score — each component's mark
- weight — its share of the total
- Weights — need not sum to 100 — the divisor handles it
A brilliant coursework mark moves a final grade far less than it feels like it should when the exam carries 70%.
Open the Weighted Grade →GPA
grade points- points — the grade point for each course
- credits — credit hours for that course
- Result — quality points ÷ total credits
Credit-weighted, so a four-credit module moves your GPA twice as far as a two-credit one.
Open the GPA Calculator →GPA vs CGPA
scope- GPA — a single term or semester
- CGPA — cumulative across all completed credits
- Effect — later terms move a CGPA less as total credits grow
The larger your completed credit total, the harder a CGPA is to shift — early terms matter more than they seem.
Open the CGPA Calculator →Working backwards
The most useful question in the week before an exam is not "what do I have?" but "what do I still need?".
Mark needed on the final
percentage- target — the overall grade you want
- current — your grade so far
- w — the final's weight as a decimal
If the result exceeds 100 the target is out of reach; if it is at or below zero you have already secured it.
Open the Final Grade →Why a light final caps you
consequence- Exam worth 40% — 60% of your grade is already fixed
- Exam worth 20% — 80% is fixed — a perfect paper adds little
- Implication — a low current grade plus a light final can be unrecoverable
Check this before revising: the weight, not the effort, sets the ceiling.
Open the Final Grade →Test score
percentage- correct — questions right
- total — questions asked
- Negative marking — not applied — some exams deduct for wrong answers
The simplest case, and the one where the letter grade depends entirely on which scale your school uses.
Open the Test Score →Key figures at a glance
How to use this page
Look a scale up here when a calculator gives you a letter you did not expect, or when you need to know which formula is being applied. Each card states the whole rule, so it also works as a reference while you are checking a transcript or planning revision. Follow the link at the foot of a card to have the arithmetic done.
Why scales differ, and what that means for you
There is no universal mapping from a percentage to a letter grade or a grade point. A 4.0 scale in the United States, a 10-point scale in India and UK degree classifications are separate systems built for separate purposes, and even within one country institutions set their own boundaries, decide whether to round at a boundary, and choose whether to weight honours courses above 4.0. That is why converting a grade between systems is an approximation at best. Use these tools to understand and check your own arithmetic; use your institution's published regulations for anything that counts.
Sources & references
Every figure on this page traces to one of these. Where the governing document is a paywalled standard we name it rather than link a shop front:
- UCAS Tariff points — how UK qualifications are converted to tariff points for university entry — a worked example of one system mapping onto another
- Your institution's academic regulations or student handbook — the only authority on your grade boundaries, credit weightings, rounding rules and classification thresholds
- The module or course specification — states each component's weighting — the input the weighted-average and final-grade tools depend on
Further reading
Weighted averages against plain ones, the mark you need on the final, and why a GPA is the same formula with credit hours as the weights.
Cite this page
You are welcome to quote these figures in a lesson, a forum answer, a wiki or a write-up. A link back is all we ask — it lets your reader check the figure against its source, which is the point of the page.
Tool Corner, “Grades & GPA Reference”. Updated 29 July 2026. https://toolcorner.net/education-reference.html
Every figure is dated, and the sources above are linked wherever a stable public page exists, so a citation here can be traced rather than taken on trust.