I still find light bulbs somewhat confusing! Trying to compare one with another is not easy given how the industry is changing and introducing new products and technology all the time. In the US, the Federal Trade Commission (FTC) has made this comparison a lot easier by requiring manufacturers to provide the same information on their labels.
These lighting facts appear on the light bulb package.
This will be stated in lumens not watts – the higher the number, the brighter the light.
ESTIMATED YEARLY ENERGY COST
This is the cost to light your bulb based on an average usage of 3 hours per day and 11c per kWh.
The life span of the product will be stated in years based on an average usage of 3 hours per day.
This gives you the Correlated Color Temperature (CCT) rating stated in Kelvins. The lower the number, the warmer the light. 2700K is similar to the old incandescent bulbs and is a warm, soft light. 3500K is the whitest light. 5000K upwards will be tinged with blue.
The energy the bulb consumes in Watts. The lower the wattage, the less energy is used and the lower the electricity costs.