Find the calculator here: https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-resistor-color-code
Resistors are classified not only by their resistive value but also by their manufactured tolerance and temperature coefficient. So, not all resistors are created equal and there is a lot of information which would be difficult to fit on the small, curvy case if it were not for the invention of color banding. In this video, interpretation of color banding is explained as well as the resources available at Digi-Key Electronics that make reading the bands a cinch.
More information on the Blog: https://www.digikey.com/en/articles/big-boys-race-young-girls-violet-wins-resistors-color-codes