It depends on the quality of your videos along with their length. Normally, 1-hour long video footage with 1080P resolution can easily consume 10 to 20GB of storage space. So, if you are buying a 1TB hard drive, it should easily store 8 to 10 hours of video footage. Keep a note that the higher the resolution and the frame rates of your video clip, the larger storage space will be required to store it.