Grade calculator
- Runs in your browser
- No signup
- Formula shown below
- Reviewed
A grade calculator finds the score still needed to reach a target course grade. Homework at 95% worth 20 and a midterm at 88% worth 30 give a grade of 90.8% across the half of the course marked so far. Finishing at an overall 90% then requires 89.2% on the remaining 50%.
Score is a percentage. Weight can be a percentage or any relative number — only the ratio matters.
Result
Overall weighted grade — A−
90.80%
G = Σ(scoreᵢ × weightᵢ) ÷ Σweightᵢ
- Letter grade
- A−
- Grade points (4.0 scale)
- 3.70
- Total weight entered
- 50
- Score needed on the remaining 50% to reach 90%
- 89.2%
- Homework (weight 20)
- 95.0%
- Midterm (weight 30)
- 88.0%
Across 2 assessments totalling 50 weight units, the weighted average grade is 90.80%, which is an A− on the standard US letter scale and 3.7 grade points on the 4.0 scale.
How to use the grade calculator
- 01
List your assessments
Enter one assessment per line in the form “name, score, weight”. Score is a percentage; weight can be a percentage or any relative number.
- 02
Add every graded item
Include homework, quizzes, labs, papers and exams. Any item left out shifts the average toward the items that remain.
- 03
Set a target grade
Type the overall grade you are aiming for. While the entered weights total less than 100, the calculator returns the score required on everything still outstanding.
- 04
Read the score needed
The result strip shows the grade so far and its letter. The rows beneath give the score required on the remaining weight, flagged when it exceeds 100% and is therefore unreachable.
The formula
G = Σ(scoreᵢ × weightᵢ) ÷ Σweightᵢ needed = (target − G × (1 − w)) ÷ w
- G
- The overall weighted grade as a percentage.
- scoreᵢ
- The percentage earned on assessment i.
- weightᵢ
- The relative weight of assessment i. Only the ratio matters, so weights need not sum to 100.
- target
- The overall grade you are aiming for.
- w
- The share of the final grade still outstanding, as a decimal.
- needed
- The score required on the remaining work to reach the target.
Weights are relative, not absolute. Entering 20, 30 and 50 gives the same answer as entering 2, 3 and 5. When the entered weights total less than 100, the calculator treats the remainder as outstanding and computes the score needed on it.
Worked example
- Assessments
- Homework 95% (weight 20) Midterm 88% (weight 30) Final exam 92% (weight 50)
- Target grade
- 90%
- Result
- 91.40% — A−
Multiply each score by its weight: 95 × 20 = 1,900, 88 × 30 = 2,640, and 92 × 50 = 4,600. Sum the products: 1,900 + 2,640 + 4,600 = 9,140. Sum the weights: 20 + 30 + 50 = 100. Divide: 9,140 ÷ 100 = 91.40%. On the standard US scale that is an A−, worth 3.7 grade points. The target of 90% is already exceeded, so no further score is required.
Frequently asked questions
How do you work out what grade you need to pass?
Take the target overall grade, subtract what the completed work already contributes, then divide by the share still outstanding. Holding 90.8% across 50% of a course and targeting 90% overall needs (90 − 45.4) ÷ 0.5 = 89.2% on the remaining half. A result above 100% means the target is out of reach without extra credit.
What score do I need on the final exam?
Use needed = (target − current × (1 − w)) ÷ w, where w is the final exam's share of the grade as a decimal. Holding 85% across 70% of the course and targeting 90% overall requires (90 − 85 × 0.7) ÷ 0.3 = 101.67% on the final — mathematically out of reach without extra credit.
What percentage is an A grade?
On the most common US scale, an A is 93 to 96%, an A+ is 97% and above, and an A− is 90 to 92%. B grades run from 80 to 89%, C from 70 to 79%, D from 60 to 69%, and F below 60%. Institutions vary, so the registrar's published scale governs any official transcript.
Do weights have to add up to 100?
No. Only the ratio between weights affects the result, so 2, 3 and 5 produce exactly the same average as 20, 30 and 50. Weights totalling less than 100 are useful mid-semester: the calculator treats the shortfall as outstanding and computes the score needed on it to reach a target.
How does dropping the lowest grade change the average?
Remove that assessment's line entirely and recalculate. Both the numerator and the denominator shrink, so the effect is larger than it first appears — dropping a 40% from a set of 90s can lift an average by several points. Where a syllabus replaces a dropped score rather than removing it, enter the replacement instead.
What is the difference between a weighted and an unweighted grade?
An unweighted average treats every assessment as equally important, which is only correct when every assessment carries the same weight. A weighted average scales each score by its stated share of the final grade. The average grade calculator handles the first case and the weighted grade calculator the second, while this page projects forward to the score still required.
Sources
- Grading and academic standing policies — reference practice — US National Center for Education Statistics
- Weighted mean — definition and method — Encyclopædia Britannica
- Ratios and proportional relationships — standards — Common Core State Standards Initiative
Last reviewed: · Formula and sources verified by Syed Aqeel Ahmad Gillani. See the methodology for how every calculation is derived.