Work out the score you need on your final exam to reach a target grade, or calculate your weighted class grade from assignments and exams.
If you have 84% and the final is worth 30%, getting a 90% overall needs (90 − 84 × 0.7) ÷ 0.3 = 104%, so a 90 isn't reachable without extra credit, but an 87 needs 94%.
The weighted grade divides by the weights entered, so it shows your grade on the work done so far.
On the common US scale, 83–86 is a B, 87–89 a B+.