Step 1
Locate your sewing machine owner's manual. Look in the "Specifications" section of the manual for the wording "Voltage" and "100-240V" next to "50/60Hz." Dual voltage sewing machines have a voltage rating of "100-240V."
Step 2
Turn your sewing machine upside down or around so the back of the device is facing you, if you can't locate your machine's owner's manual. Locate a plastic or metal sticker on the bottom of the machine containing the wording "Model Number."
Look for "100-240V" next to "50/60Hz." If you see this wording, you have a dual-voltage sewing machine.
Step 3
Pick up your sewing machine's foot pedal component, and turn it upside down if you don't see a plastic or metal sticker on the bottom or backside of the device.
Step 4
Locate a plastic or metal sticker on the bottom of the machine containing the wording "Model Number:." Look for "100-240V" next to "50/60Hz." If you see this wording, you have a dual-voltage sewing machine.