Determine the amperage of a tool that will run on the extension cord by checking the tool plate. Each tool has a metal plate showing the serial number, the model number and the amperage.
Determine the amperage of tools that list the power specification in watts and volts by writing down the wattage shown on the tool plate. Divide the wattage by the voltage to obtain the amperage. For example, if the plate indicates that a tool uses 360 watts and is 18 volt, the amperage of the tool is 360 divided by 18, or 20 amps.
Write down the amperage for each tool.
Add the amperage of each tool to get the total number of amps that will run on the extension cord.
Check the paper safety tag on the extension cord for the maximum amperage that is safe for the cord. If the cord will not handle the total amperage from the tools, use a cord with a higher safety rating.
Things You Will Need
- Pen and paper
- Determine the size of extension cord for one tool or appliance by comparing the amperage on the metal plate with the extension cord tag.