
Incandescent bulbs are around 2700-3000K and produce a yellower warm/soft light, great for creating a relaxed ambiance. Light colour is measured using a temperature scale called Kelvin (K). Choosing the colour temperature of bulbsĬhoosing the right colour is dependent on the atmosphere you’re trying to create within your room, or what the space you are lighting is used for. Bulbs that are nearer to daylight (bluer or cooler in colour) sometimes appear brighter than yellower coloured lights. The colour of light can also affect how bright a light appears, even if the lumens are the same. Incandescent Bulb Wattageĭata sources: American Association of Physics Teachers 1996 and Energy Star 2016 What else can affect brightness perception? An equivalent compact fluorescents (CFL) bulb in light output (lumens) should consume only around 7 watts and LEDs approximately 6 watts. Wattage to Brightness ComparisonĪ 40 watt incandescent filament bulb produces roughly 460 lumens. Some of the most energy to light efficient LED bulbs are now reaching over 120 lumens in Energy Star tests. On average, an incandescent bulb produces around 14 lumens per watt, compared to 63 lumens for energy saving compact fluorescents (CFL) and 74 for LED bulbs. Most of us have a preconception of how bright a 100-watt incandescent bulb is even though this can vary tremendously between soft white and clear glass bulbs.

Lumens is an accurate way of measuring the light output of bulbs – brightness is what we perceive, luminance is what we measure. They come in varying technologies, such as Compact Fluorescent (CFL), Halogen and LED and they last much longer – up to 25 years for LEDs!ĭefining the brightness, or light output of bulbs is changing from wattage equivalents to lumens. Nowadays, energy saving bulbs produce far more light, less heat, whilst consuming less energy (Watts).

In recent years choosing light bulbs has become far more confusing – you knew roughly what you were getting with a 40, 60 or 100 wattage filament bulb.

Household cost based on 12 bulbs.Įlectricity costs are calculated using the UK: Price Cap (Jul 2023) electricity rate of £0.30 per kWh (incl. *lumens conversion based on averages of Energy Star LED/CFL testing data 2016
