Well, there are 12 inches in a foot, so that would two feet of extensions. So, really long!
The actual hair extensions are 24 inches. If you are after an answer as to where the actual length will be once attached to your hair, then that would depend on how long your hair was in the first place.
Hair extensions!
Hair extensions are a fun, simple, and reasonable way to get long beautiful hair. Hair extensions are the go-to solution for thousands of women, as they give a long-lasting and simple way to add length and volume to your hair. Benefits of Tape in hair extensions The advantage of this type of hair extension for thin hair is that the single method application can be used as a solution. Instead of bonding two tape weft hair extensions together as you would for a normal tape application, one tape weft extension is placed on the hair and the other side is sealed with a single-sided piece of tape. This is the best solution for thinning hair. It gives long wear without any damage to thin hair. Tape-in extensions require no tools or chemicals.
Get extensions.
If your extensions are human hair, you can use conditioner or a de-tangler as you would you own hair; unfortunately, if they're synthetic there's not too much you can do because they don't last very long, anyway. You can gently comb through synthetic hair extensions, but they probably won't look good afterward.
Clip in hair extensions last for anywhere from 6 months to 1 year. It really depends on the usage, more than the quality of the hair. Never wear hair extensions at night.
Sounds like you're going to have to wait for it to grow.
It is not recommended that you use chemicals in attempt to lengthen your hair; you can, however, temporarily make your hair longer with clip-in, sewn in, or bonded hair extensions.
Use hair extensions.
your hair will start to get bad and split ends
Hair extensions or a wig
Yes, some NFL players with long braids are hair extensions.