“Quarter grade” means two different things
A quarter grade can mean the grade within a quarter — computed from that quarter’s assignments — or the semester/final grade built by combining quarter grades. Districts do the first in three different ways, and the second with different weight splits and even different kinds of averaging. The same scores give different answers depending on the method, so this page asks which one your school uses instead of assuming.
Within a quarter — three methods
Weighted categories. Each category (tests, quizzes, homework) has a fixed percent; the quarter grade is the weighted sum of category averages. Florence One Schools uses Project/Test 45% + Quizzes/Labs 30% + Classwork/Homework 25% per quarter. Worked example: 86 × 45 + 92 × 30 + 78 × 25 = 38.70 + 27.60 + 19.50 = 85.80%.
Total points. Add points earned, divide by points possible; bigger assignments automatically weigh more. Guilford High School’s Chemistry syllabus states it exactly: “if there were 500 points in a marking period and you earned 400 you would receive an 80 or a B for the quarter.” Worked example: 400 / 500 = 80.00%.
Equal per assignment. Every assignment in a category counts equally, whatever its maximum score — Fairfax County’s South County Middle School rule. Worked example: Quiz 9/10 (90%) + Test 60/100 (60%) → (90 + 60) / 2 = 75.00%. Total points on the same scores would give 69 / 110 = 62.73%. The method changes the answer by more than 12 points.
Quarters combined — the weighted formula
Worked example — 40/40/20 (Southwest Virginia Governor’s School, Brunswick, Florence One, CIE). Q1 88 × 40 + Q2 92 × 40 + Exam 76 × 20 = 35.20 + 36.80 + 15.20 = 87.20%.
Worked example — 45/45/10 (Somerset County Public Schools). Q1 88 × 45 + Q2 92 × 45 + Final exam 76 × 10 = 39.60 + 41.40 + 7.60 = 88.60%. Identical scores, different district rule — 1.40 points apart. Weight choice matters more than rounding.
Worked example — 85/15 (Memphis-Shelby, Dallas high school). Quarters averaged: (88 + 92) / 2 = 90.00. Semester = 90.00 × 0.85 + 76 × 0.15 = 76.50 + 11.40 = 87.90%. The same result comes from per-quarter weights of 42.5/42.5/15 — “average the quarters, then apply 85/15” and “weight each quarter 42.5%” are the same formula.
Worked example — Fort Worth ISD six-weeks, sevenths. 1st six-weeks 92, 2nd 85, 3rd 80, semester exam 78: (92 × 2 + 85 × 2 + 80 × 2 + 78 × 1) / 7 = 592 / 7 = 84.57% → 85 as a whole number. Use exact fractions (2/7, 1/7), not the district document’s rounded percents (28.5%, 14.5%). Nine-weeks: Q1 88, Q2 92, exam 76 → (88 × 3 + 92 × 3 + 76 × 1) / 7 = 616 / 7 = 88.00% exactly.
The method-matters proof: percent average vs letter-point average
Prince George’s County Public Schools averages letter grades converted to a 4-point scale (A = 4, B = 3, C = 2, D = 1, E = 0), then maps the average back through its final-grade bands (A = 3.5–4.0, B = 2.5–3.49, C = 1.5–2.49, D = 0.5–1.49, E = 0.0–0.49). Take quarter percents 90, 80, 90, 80 → letters A, B, A, B (PGCPS bands: A 90–100, B 80–89).
- PGCPS method: (4 + 3 + 4 + 3) / 4 = 3.50 → A.
- Percent method: (90 + 80 + 90 + 80) / 4 = 85.00 → B.
Same quarters, different final letter. A calculator must never silently convert percents → letters → average, and must never silently average percents, without saying which method it is using.
Named splits, each cited — none is universal
- 40 / 40 / 20 — Q1 + Q2 + exam = semester (Southwest Virginia Governor’s School; Brunswick semester; Florence One non-AP semester; CIE semester). The most attested split in this research — four independent sources — not the most common one.
- 45 / 45 / 10 — Q1 + Q2 + exam = semester (Somerset County Public Schools).
- 85 / 15 — quarters averaged 85% + exam 15% = semester (Memphis-Shelby grades 9–12; Dallas ISD high school).
- 90 / 10 — quarters averaged 90% + exam 10% = semester (Dallas ISD middle school).
- Sevenths — six-weeks: each 2/7, exam 1/7; nine-weeks: each 3/7, exam 1/7 (Fort Worth ISD).
- Equal quarters — final from quarters with no exam weight (Prince George’s County, letter-point; Fairfax County South County Middle School, percent; Dallas elementary; Somerset County grades 1–8).
Rounding — no universal rule
PGCPS rounds gradebook averages to the nearest whole number (82.4 → 82, 91.5 → 92). Fort Worth’s printed example truncates intermediate components (84.5 vs the exact 84.57). Other sources are silent on rounding. This calculator shows two decimals and rounds only for display; your school may round differently.
In-progress grades (calculator convention, labelled)
If some quarters are not finished yet, this calculator divides by the weights you entered — the standing “on completed work so far.” No district source states this normalisation. It is not a predicted final grade and not a school rule.
What the recorded grade may still change
A computed average matches the weights you entered. The recorded grade can still differ: grade floors (some schools set a minimum), teacher override, exam exemptions, retake or reassessment caps, end-of-course exam mandates, IEP modifications, and advanced-course bonus points. Check your school’s policy before treating a result as official.
Common mistakes
- Averaging percents when your school uses letter-points. Same quarters, different letter — see the proof above.
- Assuming 40/40/20 is universal. Your district may use 45/45/10, 85/15, sevenths, or equal quarters.
- Mixing total-points with equal-per-assignment. A 10-point quiz and a 100-point test count 1:1 in one method and 1:10 in the other.
- Treating a partial standing as the final grade. The in-progress number covers completed work only.
- Assuming one letter scale. Letter cutoffs vary by school — there is no single scale.
- Assuming an exam exists. Some schools have no exam weight; others drop it for exempt or state-tested students.
Full walkthrough: How to Calculate Your Quarter Grade. Midterm: Midterm Grade Calculator. Finals: Final Grade Calculator.