Lumens to candela calculator

Lumens (lm) to candela (cd) calculator and how to calculate.

Lumens to candela calculator

Enter the luminous flux in lumens, apex angle in degrees and press the Calculate button

to get the luminous intensity in candela:

	Enter luminous flux in lumens:		lm
	Enter apex angle in degrees:		º
	Luminous intensity result in candela:		cd

Candela to lumens calculator ►

Lumens to candela calculation

For uniform, isotropic light source, the luminous intensity I_v in candela (cd) is equal to the luminous flux Φ_v in lumens (lm),

divided by the solid angle Ω in steradians (sr):

I_v(cd) = Φ_v(lm) / Ω_(sr)

 

The solid angle Ω in steradians (sr) is equal to 2 times pi times 1 minus cosine of half the apex angle θ in degrees (º):

Ω_(sr) = 2π(1 - cos(θ/2))

 

The luminous intensity I_v in candela (cd) is equal to the luminous flux Φ_v in lumens (lm),

divided by 2 times pi times 1 minus cosine of half the apex angle θ in degrees (º):

I_v(cd) = Φ_v(lm) / ( 2π(1 - cos(θ/2)) )

So

candela = lumens / ( 2π(1 - cos(degrees/2)) )

Or

cd = lm / ( 2π(1 - cos(º/2)) )

 

Lumens to candela calculation ►

 

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See also

• Candela to lumens calculator
• Watts to lumens calculator
• Lumens to watts calculation
• Watt (W)
• Electrical calculation
• Power conversion

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