How it's calculated
Needed = (target − current × (1 − w)) ÷ w
target = desired final grade, current = grade so far, w = final exam weight as a fraction (e.g. 20% = 0.20).
Common questions
How do I find the grade I need on the final?
Subtract your current grade times its weight from the target, then divide by the final's weight. The calculator does this for you.
Can I still pass if my final is worth 20%?
Often yes. If you have an 80% going in and the final is 20%, even a 50% final keeps you at 74%.