How do I measure sqft in a gable? I am putting shakes in the gable and don't want a huge extra left, nor be short..

To measure the sqare foot of a gable simply measure the bottom width, then measure from the bottom of the gable to the peak. Take the two measurment times each other and divide by 2. Then take that measurement times 10% and you should be good.
example: 20' wide X 9' high = 180 180 X .5 = 90 90 x 10% = 9
90 + 9 = 99 sqare feet
There is 100 square feet of material in a square.
If you buy 1 square of shakes you should be about perfect.
Mike

Measure half the width of the gable and multiply by the height of the peak and add 15%