Two quarters plus a final exam: the standard US high school structure. Add a target to find the score you need on the final.
Per-category weights from the syllabus. Add or remove rows to match your grading breakdown.
| Category | Score (%) | Weight (%) | Remove |
|---|---|---|---|
| Total Weight | 0% | ||
How to Use the Semester Grade Calculator
The semester grade calculator above runs in two modes that match how US schools structure semester grading. Quarter + Final mode is the default; it covers the standard high school setup of two grading periods plus a cumulative final exam. Weighted Categories mode handles the alternative pattern, common in college courses and AP sections, where the syllabus assigns its own weight to homework, quizzes, midterms, and the final independently. Whether you call it a high school semester grade calculator, a 2 semester grade calculator for fall and spring rollups, or simply a semester grades calculator, the math is the same weighted average and the calculator above runs both shapes.
Both modes calculate live as you type. There is no Calculate button. The math is the same weighted-average formula your registrar applies, so the percentage shown matches what the school will eventually post to your transcript when you enter the same inputs. To switch modes, tap the tab at the top of the calculator. To reset all inputs, click Reset at the bottom of the widget.
Where to find your quarter and category grades
Your current grading period percentages live in your school's learning management system. Canvas, Blackboard, Schoology, PowerSchool, and Infinite Campus all display a running quarter percentage above the assignment list. If your gradebook only shows points, divide total points earned by total points possible and multiply by 100. For example, 412 of 500 points becomes (412 / 500) x 100 = 82.40%. The semester average calculator above accepts any percentage between 0 and 100; values above 100 are also allowed for extra-credit-heavy courses.
Where to find the final exam weight
Look in the grading-policy section of your syllabus. It typically appears as a list: Q1 40%, Q2 40%, Final 20%, or Homework 20%, Quizzes 15%, Midterm 25%, Final 25%, Projects 15%. The most common US high school structure is two equal quarters plus a 20% final. AP and honors courses sometimes weight the final at 25% or 30%. If your syllabus lists weights as point allocations rather than percentages, divide each category by the course total to convert to percentage form before entering it in Weighted Categories mode.
How Semester Grades Are Calculated
Calculating semester grades is a weighted-average problem. Each grading period contributes a fixed share of the final number, and the share comes from the syllabus. The formula generalizes to Sum(Period x Weight) divided by Sum(Weights), and reduces to a simple weighted average when there are only two grading periods plus a final. The same formula every semester calculator uses appears below in stacked-fraction form.
Quarter + Final formula (the default mode)
Semester Grade = (Q1 + Q2) / 2 x (1 - Final Weight) + Final Score x Final Weight
- Q1, Q2 = your two quarter percentages
- Final Score = your percentage on the final exam
- Final Weight = how much the final counts toward the semester, expressed as a decimal (20% = 0.20)
Weighted Categories formula
- Score = each category percentage (0 to 100)
- Weight = the percentage that category counts toward the semester
How calculating semester grades scales when quarters carry uneven weight
Most US high schools weight Q1 and Q2 equally, but block-scheduled courses, AP sections, and some districts deviate. When the quarters are unequal, switch to Weighted Categories mode and enter each grading period as its own row. The weighted-categories formula automatically handles uneven weights. With Q1 at 30%, Q2 at 30%, midterm at 15%, and final at 25%, grades of 85, 90, 80, and 88 produce (85 x 30 + 90 x 30 + 80 x 15 + 88 x 25) / 100 = 86.50%, which is a B on the standard scale. The same approach works for marking-period systems with three or four grading periods per term.
Calculate average percentage on a semester average calculator (percent average calculator method)
The same math powers a semester average calculator, a percent average calculator, and a work out average calculator: each computes a weighted average across grading periods and converts the percentage result to a letter grade. To calculate average percentage manually, multiply each period's grade by its weight (as a decimal), sum the products, and divide by the sum of weights. The semester average calculator above runs the calculation live for the standard quarter-plus-final structure; the percent average calculator pattern in the Weighted Categories mode handles arbitrary period weights. Calculating semester average for the most common US high school setup with two equal quarters and a 20% final reduces to (Q1 + Q2) / 2 x 0.80 + Final x 0.20.
Marking period grade calculator and quarter grade calculator: the same math
A marking period grade calculator and a quarter grade calculator solve identical math; the names reflect regional vocabulary. School districts in the Mid-Atlantic and Northeast often use "marking period" while the rest of the US says "quarter". Whichever term your school uses, the marking period grade calculator workflow is the same: enter each marking-period percentage and weight, then the final exam if your course has one. The semester grade calc above accepts both naming conventions; treat each marking period as a quarter input or use Weighted Categories mode with one row per marking period. A 4 marking period grade calculator for trimester or quarter-plus-trimester systems uses the same Sum(Period x Weight) / Sum(Weights) formula with one row per period.
Quarter + Final and Weighted Examples
Worked examples make the formula concrete. The scenarios below cover an AP course with a heavier final, a regular high school course on the standard 20% final weight, and a college course using full weighted categories.
AP US History: Q1 88%, Q2 92%, final 80%, final weight 30%
AP and honors courses commonly weight the final at 25% or 30% to reflect the cumulative scope of the assessment. With a 30% final, the math is Semester = (88 + 92) / 2 x 0.70 + 80 x 0.30 = 90 x 0.70 + 80 x 0.30 = 63 + 24 = 87.00%. That is a B+ on the standard 10-point scale. Note how the heavier final pulls the semester grade further from the quarter average than a 20% final would; a 78% final would land the semester at 86.40% versus 87.60% under the standard weight.
Honors Algebra: Q1 75%, Q2 82%, target B (83%)
Without a final score yet, Quarter + Final mode flips into backward-solve territory when you fill in a target. The math is Required Final = (Target - Quarter Average x (1 - Final Weight)) / Final Weight. With a quarter average of 78.5% and a 20% final, reaching a B (83%) requires (83 - 78.5 x 0.80) / 0.20 = (83 - 62.80) / 0.20 = 101%. That is just over the maximum without extra credit, so the calculator flags it as out of reach. Lowering the target to 80% drops the required score to 86%, which is comfortably achievable.
College Composition: weighted categories with drop-lowest
A typical college semester course uses Weighted Categories mode with four to six rows. Suppose your syllabus reads Homework 25%, Quizzes 15%, Tests 30%, Final 30%, with grades of 95%, 88%, 78%, and 85%. The weighted average is (95 x 25 + 88 x 15 + 78 x 30 + 85 x 30) / 100 = 86.45% (B). With Drop Lowest checked and three or more rows, the calculator excludes the single lowest score from the average, which reflects classroom policies that drop the weakest quiz or test before computing the final grade.
Calculating Semester Grades Without a Final Exam
Some courses do not include a cumulative final exam. Project-based seminars, lab courses, and a small minority of districts use only marking-period grades to determine the semester result. Use this semester grade calculator without final exam mode by leaving the Final Exam Score field blank and setting Final Exam Weight to 0; the calculator returns the simple quarter average. With Q1 of 87% and Q2 of 91%, the semester is (87 + 91) / 2 = 89%, a B+ on the standard plus-minus scale. An end of semester grade calculator behaves the same way once the final score is in: enter the final percentage and the result reflects the full term.
Mid-semester estimates work the same way. If Q2 has not been graded yet but you want a working projection, enter only Q1 and the calculator will display your single-quarter average as the pre-final standing. Once Q2 posts, rerun the calculation with both quarters for the official semester grade. The same approach lets you model "what if Q2 lands at X" scenarios before the official grade is in.
Semester Grade vs Semester GPA
Semester grade and semester GPA are two distinct numbers that schools report on different parts of your academic record. A semester grade is a single course percentage or letter for one term, calculated by averaging that course's assignments and exams. A semester GPA is the weighted average of grade points across every course you took that term, calculated by converting each letter grade to its 4.0-scale point value, multiplying by the course credit hours, and dividing by total credits.
The calculator above produces a per-course semester grade. To find your semester GPA across multiple courses, use the GPA calculator. To track GPA across multiple terms, use the cumulative GPA calculator. Both tools accept the per-course letter grade output you generate here, so the standard workflow is: calculate each course's semester grade with this tool, convert to letters, then enter the letters and credit hours in the GPA calculator for the term-level GPA.
Quarter grade calculator vs semester grade calculator
A quarter grade calculator and a semester grade calculator answer different questions on the same timeline. The quarter calculator computes a single grading-period grade from category scores within that quarter (homework, quizzes, tests). The semester grade calculator combines two completed quarter grades plus a final exam into the term result. Use the grade calculator for the quarter-level math; use this page for the semester rollup once both quarters are graded.
Why Your Calculated Grade May Differ From Your School's
A calculated semester grade can differ from the gradebook output by a few percentage points. There are four common reasons, and resolving the gap usually means matching one of them.
- Rounding rules. Some districts round 89.5% up to 90% (A-), while others use a flat floor that holds 89.5% at 89% (B+). Check your school's grading handbook for the exact rule.
- Dropped scores. Many teachers drop the lowest quiz or test before averaging. The calculator handles this when Drop Lowest is checked in Weighted Categories mode. If the gradebook applies it but the calculator does not, the numbers will not match.
- Participation and attendance. Some syllabi include a small participation or attendance category (5 to 10%) that does not appear in the standard quarter-plus-final formula. Add it as a row in Weighted Categories mode.
- Wrong syllabus weight. Sometimes the syllabus lists a weight the teacher did not actually apply, or the weight changed mid-semester. Confirm the official weight with your teacher or registrar before treating any calculator result as definitive.
Always verify the official weights, rounding policy, and dropped-score rule with your specific school. The math in this calculator is exact for the inputs given, but the inputs themselves are governed by school-level policies that vary district to district. For broader course-grade calculations, use the grade calculator; for the score you need on a final exam in any single course, use the final grade calculator.
Grading conventions and weighting norms in this article draw on the American Association of Collegiate Registrars and Admissions Officers and the College Board. Always confirm semester-grade policy with your specific school's registrar.