So you've received all your grades and you know the weighting of each part but what is your final weighted mark? Sure you can wait for your teacher to publish everyone's marks, but what if you want to know now. So how do you calculate your final grade? It's actually really easy so grab a calculator and we'll start.

The easiest way to explain this is with an example. Emma has got 76% for her first assessment which is worth 20% of her final grade. On her second assessment she got 82% and this is also worth 20% of her final grade. On the final, which is worth 60%, she scored 84%. So what's her final mark?

You multiply the mark by the weighted percentage as a decimal and add them together. So for Emma the sum is (76 x 0.2) + (82 x 0.2) + (84 x 0.6) = 82.

This means Emma's weighted average grade is 82% overall.

Now what if Emma hasn't taken her final yet? With the 76% and 82% scored so far her mark is 31.6% out of a possible 40%. But what is the weighted average. All you need to do here is divide the score by the amount it is from and then multiply by 100 so:

31.6/40 x 100 = 79%

Emma now wants to know what he needs to score of her final to increase her grade to 85%. To do this she needs to use the following formula:

The formula is:

(wg x m1)+(fg x fm)=dg

where:

wg = the weighting of your current mark

m1 = your current weighted average

fg = the weighting of your final

fm = the mark on your final

dg = your desired grade

so we plug in Emma's figures to get:

(0.4 x 79) + (0.6 x fg) = 85

31.6 + 0.6fg = 85

0.6fg = 53.4

fg = 53.4/0.6

fg = 89

This means that Emma would need 89% on her final to score 85% overall. She can also change the desired grade and rework the sum to find what she needs for any grade.

Working out your weighted average is quite easy but sometimes you might not have a calculator to hand or your calculator is a basic one which doesn't allow you to use brackets and so you have to remember the answer for each part, or write them down, for adding at the end. Working out what you need on your final can be very time consuming when you need to redo the sum for each desired grade.