Watts to Candlepower Calculator
Enter the values of power, P(W) and performance factor, PF(lumens) to determine the value of Candlepower, C(W).
Watts to Candlepower Formula:
Watts to candlepower conversion helps us understand the perceived brightness of a light source based on its electrical power consumption. We measure electrical power in watts, while candlepower represents the perceived light intensity.
In the realm of illumination, candlepower isn’t a direct measure of light output, but rather a representation of our perception of a light source’s brightness.
Imagine holding a lit candle – the perceived intensity of that light is roughly the baseline for one candlepower. While power (W) quantify the electrical power a light consumes, candlepower focuses on how bright a light appears to our eyes.
Therefore, a light source with a higher wattage or a higher performance factor will generally have a higher candlepower, leading to a brighter perceived light. This understanding helps us choose lighting that balances desired brightness with energy efficiency.
For example, a high-wattage incandescent bulb with a low PF might have a similar candlepower to a lower-wattage LED bulb with a high PF, even though the LED uses less energy.
Candlepower, C(W) in watts is calculated by multiplying the power, P(W) in watts by the performance factor, PF(lumens) of the light source in lumens and then dividing by a constant value (12.57).
Candlepower, C(W) = P(W) * PF(lumens) / 12.57
C(W) = candlepower in watts, W.
P(W) = power in watts, W.
PF(lumens) = performance factor in lumens.
Watts to Candlepower Calculation:
- An incandescent bulb uses 60 watts (W) and has a performance factor (PF) of 1.8 lumens. What is the candlepower?
Given: P(W) = 60 W, PF(lumens) = 1.8 lumens.
Candlepower, C(W) = P(W) * PF(lumens) / 12.57
C(W) = 60 * 1.8 / 12.57
C(W) = 8.6W.
- An LED flashlight has a candlepower of 150 cp and a performance factor of 20 lumens. How much power (watts) does it use?
Given: C(W) = 150 cp, PF(lumens) = 20 lumens.
Candlepower, C(W) = P(W) * PF(lumens) / 12.57
P(W) = C(W) * 12.57 / PF(lumens)
P(W) = 150 * 12.57 / 20
P(W) = 9.43W.