When planning drapery rod installation it's important to keep in mind the finished effect you are trying to achieve. So don't fix the pole where it 'looks nice', but consider where the drapes will hang in relation to the window.
There are normally two features of rods and poles which have to be taken into account with drapery rod installation. These will affect the final length of your pole.
My advice is to always install the rod or pole before you make up your drapes.
Install first, then take measurements.
Decide where your drapes will be positioned. (Refer to the proportions page for more details - coming soon.)
The top of the drapes should comfortably cover the top of the window. Make allowances for the stackback space.
Remember that the rings on the far left and right of the brackets will act as 'anchors', because they can't move past the brackets.
Once you know where the drapes will be situated, you can then work out the position of the brackets for your drapery rod installation.
The last ring on the left of the drape will be on the left of the bracket, so position the bracket just to the right of this ring.
The hook or anchor pin in the drape will locate into the small eyelet on the bottom of the ring. From this you can see how high up the pole should be. You may find it easier to hold up the pole (with one ring on it) and bracket against the wall to make sure you get the position right.
Mark the position of the brackets, leaving 2" (5cms) between the outside of the bracket and the start of the finial (B).
Mark the drill hole position of one bracket and fix it securely.
Hold the other bracket in position and place the pole in both brackets. Check that the pole is level to the eye. Don't use a spirit level - uneven ceilings and floors can make a level pole look as if it's not level.
Mark the position of the bracket holes and fix securely.
Measure how much of the pole will be inserted into the finial to secure it (C).
Cut the pole to the correct length, being careful to allow for the amount beyond the brackets (2" (5cms) plus the amount taken up by the finial).
Length of pole = A + (B × 2) + (C × 2)
If the pole needs it, fit a center bracket (refer to manufacturer's instructions). Wood poles of 35mm diameter will need a center bracket if they are over 5'0" long (1.50m).
Place the rings in position on the pole, remembering to:
You may find it easier to head up your drapes and insert the hooks before you put the rings on the pole. That way you'll know exactly how many rings you'll need.
Attach the finials and fix with screws if applicable. Some brackets also have small screws which you screw in to firmly fix the pole and stop it moving in the brackets.
Whenever you install curtain rods or poles, work backwards from how you want the drapes to look. Decide the best position for the drapes, then work out where the pole should go to achieve this.
If it helps, attach old fabric or sheets to the window to help determine where the drapes should be. Then you can see where the pole or rod needs to be fixed to get this effect.