Grading Methodology: How Every EasyGrade Calculator Works

This grading methodology page explains the exact formulas, rounding rules and letter-grade cutoffs behind every calculator on EasyGrade, so you can check any result by hand and know what the tools do not do.

Last reviewed October 2026. Questions or corrections: contact us.

Grading methodology: the quick answer

Every calculator turns the numbers you type into a percent, then compares that percent with the cutoffs of the grading scale you choose. A score at or above a cutoff earns that grade. Averages use plain arithmetic on your own numbers, needed scores are rounded up to two decimals so you never fall short, and nothing you type is sent to a server. Your own teacher or school sets the official rules. See the disclaimer.

Formulas used by each grading calculator

These are the formulas in plain words. Each calculator page repeats its own formula in its quick answer.

Calculator	Formula
Test grade	(total points − points missed) ÷ total points × 100
Quiz grade	Average of the quiz percents, or total earned ÷ total possible. You choose. The lowest quizzes can be dropped.
Points-based	total earned ÷ total possible × 100
Grade average	sum of the grades ÷ number of grades. The lowest can be dropped.
Weighted grade	sum of (grade × weight) ÷ sum of weights
Final grade	score needed = (target × 100 − current grade × (100 − final weight)) ÷ final weight
Midterm grade	Same idea as the final, with the midterm weight, and an optional range if a final is still to come.
GPA	sum of (grade points × credits) ÷ sum of credits
Percentage to letter	The first grade, from the top, whose minimum is at or below the percent.
Semester grade	Weighted average of the parts of the semester.
Course, class, quarter	Weighted categories or total points, with ungraded work left out.
Grade curve	Flat add, top score to 100%, square root, or linear stretch, with an optional 100% cap.

Grading methodology worked examples you can check

• Test: a 40-question test with 6 missed is (40 − 6) ÷ 40 × 100 = 85%.
• Weighted: tests 88% worth 60 and homework 95% worth 40 gives (88 × 60 + 95 × 40) ÷ 100 = 90.8%.
• Final: a 84% grade, a final worth 30%, and a target of 85% needs (85 × 100 − 84 × 70) ÷ 30 = 87.333…, shown as 87.34% because needed scores round up.
• GPA: a 3-credit A and a 4-credit B on the 4.0 scale is (4.0 × 3 + 3.0 × 4) ÷ 7 = 3.4286, shown as 3.43.

Letter grade cutoffs and the at-or-above rule

A letter grade is found by checking the scale from the top. The first grade whose minimum is at or below your percent is your grade. On the standard scale (A 90, B 80, C 70, D 60, F 0) a score of 90% is an A and 89.99% is a B. The plus/minus scale uses 97, 93, 90, 87, 83, 80, 77, 73, 70, 67, 63 and 60. You can also build a custom scale of 2 to 20 grades. Labels may be up to 6 characters and must be unique, minimums must fall strictly from the top, and the lowest grade must start at 0. See the grading charts for the standard scales.

Rounding rules in the grading methodology

By default, results are graded on the exact value, not a rounded one. So 89.6% is shown as 89.6% (or 90% if you show 0 decimals) but is still a B. The Round before grading option changes that: the percent is rounded to the decimals you show, then graded, so 89.6% shown as 90% becomes an A. Use it only if your teacher rounds before assigning letters. Scores you need are always rounded up to two decimals, because rounding down could leave you a hair short.

How accurate is the arithmetic?

Decimal numbers like 0.1 cannot be stored exactly by ordinary computer floating-point maths, which can push a score a hair across a cutoff. The calculators use exact fractions (BigInt) for percents, cutoffs and needed scores, so a score that is exactly on a cutoff lands on the right side. On the quarter, midterm, course, class, curve and scale pages the digits you type are read exactly. On the older pages the number is first read by the browser and then converted, which is exact up to about 15 significant digits. A value with 16 or more digits can be rounded, which does not matter for real grades. If a browser lacks BigInt, the page says it needs a current browser instead of guessing.

Extra credit, drops and ungraded work

Scores above 100% are allowed, so extra credit works: an earned score may be higher than the points possible. Dropping the lowest grades removes them before averaging and never removes more grades than you have. Work with an empty score is treated as not graded yet on the course, class and quarter calculators and is left out, unless you choose to count blanks as zero where the page offers that. A zero you type is counted as a zero.

Privacy and what is stored

Calculations run in your browser. Your grades are not uploaded and not saved. The only thing the site remembers is your grading scale choice, kept in your browser’s local storage under one setting so it carries from page to page. Clearing site data removes it. See the privacy policy.

How the calculators are tested

Each calculator is checked with automated tests of its own rules, with thousands of randomly generated cases compared against a separate exact-fraction calculation written independently, and in a real browser at a 360-pixel phone width. These tests lower the chance of errors but cannot prove there are none. If you find a result that looks wrong, please tell us and include the numbers you entered.

What the calculators do not do

• They do not know your school’s policies, such as rounding, dropped work, or caps on extra credit.
• They are estimates for planning, not official grades. Your teacher’s gradebook is the record.
• Curve and what-if tools show a possibility, not what your teacher will do.

Read the full disclaimer.

Related tools

• Easy grader for a quick grade from points.
• Weighted grade calculator for categories with weights.
• Grading scale calculator to build your own scale.
• Grading charts for printable letter and GPA charts.

Grading methodology questions