Replace an ordinary light bulb with an energy-efficient one and keep the same light intensity – 3 easy steps

Replace an ordinary light bulb with an energy-efficient one and keep the same light intensity – 3 easy steps

As new energy-efficient light bulbs have appeared in stores, so has a new way of calculating the brightness. How should I know to replace an ordinary light bulb with an energy-efficient one but keep the same light intensity? For example, an ordinary 60W light bulb is replaced by an LED or 10-15W CFL light bulb….