Electromagnetic waves come in different forms, all of them a form of light. visible light is included in the electromagnetic spectrum
All electromagnetic waves travel at the speed of light.
The speed of electromagnetic waves depends somewhat on the materialthrough which they're traveling. In vacuum (no material at all), the speed is 299,792,458 meters (186,282 miles) per second.
The answer is wavelength times frequency.
The speed of light in a vacuum has been defined as exactly 299,792,458 meters per second.