11 min read
Why this matters
Before finals week, students want a clear target: what score do I need to get the grade I want? The answer depends on your current course average and how much the final exam counts toward your total grade.
The formula
Required Final % = (Target Grade − Current Grade × (1 − Final Weight)) ÷ Final Weight. If the final is worth 40% of your grade, then w = 0.40. Plug in your numbers and solve.
Worked example
Current grade: 85%. Target: 90%. Final worth 40%. Required = (90 − 85 × 0.60) / 0.40 = (90 − 51) / 0.40 = 97.5%. You need 97.5% on the final to finish with a 90% in the course.
When it's impossible
If the required score is above 100%, you cannot reach your target through the final alone — even a perfect exam won't get you there. Consider adjusting your goal or speaking with your instructor about extra credit.
Study smarter
Once you know your target, prioritize study time on high-weight topics. Update your weighted grade calculator as you receive new assignment scores so your current grade stays accurate.
Get the current grade right first
The formula is only as good as the current average you type. If Canvas still has unposted quizzes or a dropped-lowest rule you forgot, your “85%” may actually be 82%. Recalculate the course with the weighted or Canvas tool, then paste that number into the final-grade calculator.
How weight is defined
If the syllabus says “the final is 40% of the course,” use 40. If it says “the final is 200 points out of 500,” that is also 40%. Do not enter 200 as the weight unless you are in points mode. Mixing a percent current grade with a point weight will invent a nonsense required score.
Already-met and impossible results
Already met means even a zero (or a very low score) keeps the letter — still check for a minimum-final rule. Impossible means a 100% cannot reach the target. The honest move is to lower the letter goal or ask about remaining assignments, not to assume the calculator is “wrong.”
Multiple finals or a practical plus a written paper
If you have two remaining assessments, treat them as one combined weight only when they are scored as a single bucket. If they are separate (lab practical 15%, written 25%), use the weighted grade calculator to model both, or run the final-grade tool twice with updated current grades after the first exam.
EOC and other high-stakes tests
A state End-of-Course exam is not a teacher-written final. Use the EOC calculator when your district publishes a specific EOC weight (Florida can require 30% for certain courses; Texas rules vary by district). Use this guide’s tool for classroom finals, including reverse and drop-lowest modes.
A second worked example
Current 78%, want 80%, final 25%. Required = (80 − 78 × 0.75) / 0.25 = (80 − 58.5) / 0.25 = 86%. That is a B on many US scales — a realistic weekend of study, not a miracle. Compare that with wanting 90%: required = (90 − 58.5) / 0.25 = 126%, which the calculator will flag as impossible.
Try it yourself
Use the calculator below with your own numbers.
Required on final
97.5%
You need 97.5% on your final.
Recalculate with updated scores
Update your weighted average after new assignments.