There is nothing that will make your room fall flat faster than bad window treatments. And unfortunately, we are setup to fail from the very beginning. This may come as a complete shock to you, but you will most likely NOT be able to buy curtains off-the-rack from Target. They're just too short. I am not sure where the disconnect is between retailers and manufacturers, but the fact remains that those 84" panels in the store are not going to fit. The #1 rule to hanging curtains is that you want to hang them high and wide. If that is the only thing you take away from this post, you will succeed. Hanging curtains high and wide gives the appearance that your windows are just that, taller and wider! And who doesn't want bigger windows? Your space will appear larger and that can make all the difference in a small room.
Here is the basic math, which I will cover in more detail later. In a home with average 8' ceilings, the windows are typically hung even with the door, which is 6' 8" (80"). Then add another 4" for trim. (Here is where they probably get the 84" from). But, you ALWAYS want to hang your curtains ABOVE the window casing by at least 6-8 inches. So the shortest possible length for your curtains would be 90".
Now here's the thing ... this isn't an exact science, but more of a rule of thumb. An 8 foot ceiling is quite low, so in that case, I would personally hang the curtain as close to the ceiling as possible, just below the crown molding. It will draw your eye upward and make your room feel larger. As you increase your ceiling height, the more room for personal preference. I find splitting the difference is usually a good place to start, and typically end up somewhere around 2/3 the way up for 9 feet and half way for 10. The higher the ceiling, the closer you might want to hang the rod to the window, but never closer than the 6-8" rule.
The final step in deciding the correct length is to determine the style you are looking for. Are they functional or decorative? Do you want a tailored look or something bold and dramatic? When you measure length for curtains, you always want to consider how you are hanging them:
Ring Clips = measure from the inside of the clip
Grommets/Tabs = measure from the top of the rod
Hooks for specialty pleats = measure from the bottom of the rod
Once you know your floor to top of the curtain height, you can adjust based on style. Additionally, if you are ordering from a retailer that offers extra-long options, chose the longest option closest to your needs and have them hemmed to the exact length. Never, ever get something that is "close" but still short.
The three most common styles are:
Next let's tackle width. How wide do you need to hang your curtains? Well, when you push them open, you want to expose as much window as possible and let in all that natural light. Half a windows worth of curtains is not going to fit into a tiny, 4" space between your window and the end of the rod. A good rule of thumb is to extend your rod by 10-12 inches on either side. Of course this also means you may need extra-wide curtains, or you can always use 2 panels per side. You will want to double the width of the window to get the minimum width per panel. That will still give you a soft, folded look when they are pulled closed, and also an appropriate amount of fullness when they are opened (for an extra full look, you can go as much as 3x the window width). You don't want them to look like a flat sheet when they are closed. Now, perhaps you have roman shades or woven blinds, and your curtains are just being used to soften the edges and will remain open. You will still mount them wide, but you probably only need 1.5 times the width.
Having your draperies professionally made will also save you a headache if you want a specific pleat. The calculations I provided earlier are for standard, ripple fold and grommet curtains. If you have any type of specialty pleat, you will need to factor in the return (how much extra fabric is used in creating the pleat) so that you have enough fabric to close your curtains properly. For a casual look, Ripple or Grommet are your best bet. These are also the pleat options you are going to find from store-bought draperies. I would avoid using the method of sliding the rod through the top pocket. It never looks good. Buy ring clips and use those instead. Tabs are not my favorite either but slightly less offensive than the pocket. For a more pulled-together look, Tailored and Inverted pleats are a great option. Pinch pleat and the French pleat create a more formal look, and Goblet pleats are the most dramatic and look best in primary bedrooms and formal dining rooms .
I hope you found this post helpful! Curtains can be intimidating, especially if you're not the best at math. Your best option is to use a company that will professionally measure for you, but if not, at least find a friend to help you measure. To make it even easier, I created this free download to help you. Don't forget, Tiger Oak offers a Home Styling option that includes custom draperies and is available nationwide!
"When your home shows up well for you, you can show up well for others."