How to choose the extension cord
Ask yourself these questions when choosing the best extension cord for the job.
1. How far away is the outlet you will be using?
2. Will you be working indoors or outdoors?
3. What is the total wattage of the tool(s) or appliance(s) you will be using?
if you want to plug in devices all along its length.
Notes on extension cords
The further away you are from the outlet, the longer your extension cord must be, and this reduces the amount of current that the cord can deliver. A 16 gauge cable that is less than 50 feet long can deliver 1625 watts for powering your tools, but if the cable length exceeds 50 feet, you will only have 1250 watts of available power.
Extension cords that are suitable for outdoors use will be marked "Suitable for Use with Outdoor Appliances" directly on the cable jacket.
The amount of wattage required for operation of your tool or appliance will be marked directly on the device. If your extension cord will need to power more than one device at the same time, then you can simply add together these wattage ratings to determine your total wattage.
If the rating on your tool or appliance is listed in amps rather than watts, simply multiply the amps by 125 to get your wattage (for example, 5 amp tool will require 625 watts-125x 5).