Category Archives: calculators

Watts to lux calculator

Watts to lux calculator with calculation formula

Electric power in watts (W) to illuminance in lux (lx) calculator and how to calculate.
Enter the power in watts, luminous efficacy in lumens per watt, surface area in square feet / meters or spherical radius in feet / meters and press the Calculate button to get the illuminance in lux:

Enter power in watts:  
W
Select light source
Or enter luminous efficacy in lumens per watt:
lm/W
Enter surface area:  
Or enter spherical radius:  
   
 
   
Illuminance result in lux:  
lx


Watts to lumens calculator

Calculation formula for Watts to lux conversion:

Watts to lux calculation with area in square feet

The illuminance Ev in lux (lx) is equal to 10.76391 times the power P in watts (W), times the luminous efficacy η in lumens per watt (lm/W) divided by the surface area A in square feet (ft2):

Ev(lx) = 10.76391 × P(W) × η(lm/W) / A(ft2)

Watts to lux calculation with area in square meters

The illuminance Ev in lux (lx) is equal to the power P in watts (W), times the luminous efficacy ηin lumens per watt (lm/W) divided by the surface area A in square meters (m2):

Ev(lx) = P(W) × η(lm/W) / A(m2)

Watts to lumens calculator

Watts to lumens light conversion calculator

Electric power in watts (W) to luminous flux in lumens (lm) calculator with conversion formula.

How to calculate?

Enter the power in watts, luminous efficacy in lumens per watt and press the Calculate button to get the luminous flux in lumens:

Enter power in watts: W
Enter light source:
Or enter luminous efficacy in lumens per watt: lm/W
   
Luminous flux result in lumens: lm

Millicandela to lumens calculator

Calculation formula for watts to lumens conversion

Energy saving lamps have high luminous efficacy (more lumens per watt).

The luminous flux ΦV in lumens (lm) is equal to the power P in watts (W), times the luminous efficacy η in lumens per watt (lm/W):

ΦV(lm) = P(W) × η(lm/W)

Millicandela to lumens calculator

Millicandela to lumens calculator

Millicandela (mcd) to lumens (lm) calculator with conversion formula.

How to calculate?

Enter the power in watts, luminous efficacy in lumens per watt, surface area in square feet / meters or spherical radius in feet / meters and press the Calculate button to get the illuminance in lux:

Enter Luminous intensity result in millicandela: mcd
Enter apex angle in degrees: °
   
luminous flux result in lumens: lm


Lux to watts calculator

The conversion formula for millicandela to lumens are:

For uniform, isotropic light source, the luminous flux Φin lumens (lm) is equal to the luminous intensity Iv in millicandela (mcd),

times the solid angle Ω in steradians (sr) divided by 1000:

Φv(lm) = Iv(mcd) × Ω(sr) / 1000

 

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 (°):

Ω(sr) = 2π(1 – cos(θ/2))

 

The luminous flux Φin lumens (lm) is equal to the luminous intensity Iv in millicandela (mcd),

times 2 times pi times 1 minus cosine of half the apex angle θ in degrees (°) divided by 1000:

Φv(lm) = Iv(mcd) × ( 2π(1 – cos(θ/2)) ) / 1000

So

lumens = millicandela × ( 2π(1 – cos(degrees/2)) ) / 1000

Or

lm = mcd × ( 2π(1 – cos(°/2)) ) / 1000

Lux to watts calculator

Lux to watts conversion calculator

Illuminance in lux (lx) to electric power in watts (W) calculator

How to calculate the power in watts?

Enter the illuminance in lux, luminous efficacy in lumens per watt, surface area in square feet / meters or spherical radius in feet / meters and press the Calculate button to get the power in watts:

Enter illuminance in lux:  
lx
Select light source:
Or enter luminous efficacy in lumens per watt:
lm/W
Enter surface area:  
Or enter spherical radius:  
   
 
   
Power  result in watts:  
W


Lux to lumens calculator

*the predefined luminous values are typical or average values.

Conversion formula:

Lux to watts calculation with area in square feet

The power P in watts (W) is equal to the 0.09290304 times the illuminance Ev in lux (lx) times the surface area A in square feet (ft2), divided by the luminous efficacy η in lumens per watt (lm/W):

P(W) = 0.09290304 × Ev(lx) × A(ft2) / η(lm/W)

Lux to watts calculation with area in square meters

The power P in watts (W) is equal to the illuminance Ev in lux (lx) times the surface area A in square meters (m2), divided by the luminous efficacy η in lumens per watt (lm/W):

P(W) = Ev(lx) × A(m2) / η(lm/W)

Lux to lumens calculator

Lux to lumens calculator

How to calculate Illuminance in lux (lx) to luminous flux in lumens (lm)

Steps to calculate:

Enter the illuminance in lux (lx), select area unit type, enter radius in meters for spherical light source or surface area
in square meters for any light source and press the Calculate button to get the luminous flux in lumens (lm):

Enter Illuminance in lux: lx
Select area unit type:  
Enter spherical radius:
Or enter surface area:
   
Luminous flux result in lumens: lm

Lux to Footcandles calculator

Conversion formula of Lux to lumens:

Calculation with area in square feet

The luminous flux ΦV in lumens (lm) is equal to 0.09290304 times the illuminance Ev in lux (lx) times the surface area A in square feet (ft2):

ΦV(lm) = 0.09290304 × Ev(lx) × A(ft2)

 

The luminous flux ΦV in lumens (lm) is equal to 0.09290304 times the illuminance Ev in lux (lx) times 4 times pi times the squared sphere radius r in feet (ft):

ΦV(lm) = 0.09290304 × Ev(lx) × 4⋅π⋅r(ft) 2

 

Calculation with area in square meters

The luminous flux ΦV in lumens (lm) is equal to the illuminance Ev in lux (lx) times the surface area A in square meters (m2):

ΦV(lm) = Ev(lx) × A(m2)

 

The luminous flux  ΦV in lumens (lm) is equal to the illuminance Ev in lux (lx) times 4 times pi times the squared sphere radius r in meters (m):

ΦV(lm) = Ev(lx) × 4⋅π⋅2(m2)

Lux to footcandles conversion calculator

Lux to footcandles calculator

Illuminance in lux (lx) to footcandles (fc) conversion calculator.

How to convert?

Enter the illuminance in lux (lx) and press the Calculate button to get the illuminance in footcandles (fc):

Enter illuminance in lux: lx
   
Illuminance result in footcandles: fc

Lux to candela calculator

Conversion formula of lux to footcandle conversion

The illuminance Ev in footcandles (fc) is equal to the illuminance Ev in lux (lx) times 0.09290304:

Ev(fc) = Ev(lx) × 0.09290304 = Ev(lx) / 10.76391

Lux to candela calculator

Lux to candela calculator

calculate the value of lux to candela.Illuminance in lux (lx) to luminous intensity in candela (cd)

How to calculate?

Enter the illuminance in lux, distance from light source, select units in feet or meters and press the Calculate button
and get the luminous intensity in candela:

Enter illuminance in lux: lx
Enter distance and select feet or meters:
   
Luminous intensity result in candela: cd


Lumens to watt calculator

Calculations of lux to candela:

Lux to candela calculation with distance in feet

The luminous intensity Iv in candela (cd) is equal to 0.09290304 times the illuminance Ev in lux (lx),

times the square distance from the light source d2 in square feet (ft2):

Iv(cd) = 0.09290304 × Ev(lx) × (d(ft))2

Lux to candela calculation with distance in meters

The luminous intensity Iv in candela (cd) is equal to the illuminance Ev in lux (lx),

times the square distance from the light source d2 in square meters (m2):

Iv(cd) = Ev(lx) × (d(m))2

Lumens to watts calculator

Lumens to watts calculator

How to calculate?

To calculate Luminous flux in lumens (lm) to electric power in watts (W) calculator.
Enter the luminous flux in lumens, luminous efficacy in lumens per watt and press the Calculate button to get the power in watts:

Enter luminous flux in lumens: lm
Enter light source:
Or enter luminous efficacy in lumens per watt: lm/W
   
Power result in watts: W


Lumens to millicandela calculator

Calculation formula of Lumens to watts calculator

Energy saving lamps have high luminous efficacy (more lumens per watt).

The power P in watts (W) is equal to the luminous flux ΦV in lumens (lm), divided by the luminous efficacy η in lumens per watt (lm/W):

P(W) = ΦV(lm) / η(lm/W)

Lumens Incandescent
light bulb
(watts)
Fluorescent
 / LED
(watts)
375 lm 25 W 6.23 W
600 lm 40 W 10 W
900 lm 60 W 15 W
1125 lm 75 W 18.75 W
1500 lm 100 W 25 W
2250 lm 150 W 37.5 W
3000 lm 200 W 50 W

Lumens to millicandela calculator

Lumens to millicandela calculator

Lumens (lm) to millicandela (mcd) calculator

How to calculate Luminious flux in Lumens to millicandela

Enter the luminous flux in lumens, apex angle in degrees and press the Calculate button
to get the luminous intensity in millicandela:

Enter luminous flux in lumens: lm
Enter apex angle in degrees: °
   
Luminous intensity result in millicandela: mcd


Lumens to lux calculator

Calculations of Lumens to millicandela

For uniform, isotropic light source, the luminous intensity Iv in millicandela (mcd) is equal to 1000 times the luminous flux Φin lumens (lm),

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

Iv(mcd) = 1000 × Φv(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 (°):

Ω(sr) = 2π(1 – cos(θ/2))

 

The luminous intensity Iv in millicandela (mcd) is equal to 1000 times the luminous flux Φin lumens (lm),

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

Iv(mcd) = 1000 × Φv(lm) / ( 2π(1 – cos(θ/2)) )

So

millicandela = 1000 × lumens / ( 2π(1 – cos(degrees/2)) )

Or

mcd = 1000 × lm / ( 2π(1 – cos(°/2)) )

Lumens to lux calculator

Lumens to lux calculator

How to calculate?

Luminous flux in lumens (lm) to illuminance in lux (lx)
Enter the luminous flux in lumens, select area unit type, enter radius in meters for spherical light source or surface area
in square meters for any light source and press the Calculate button to get the illuminance in lux:

Enter luminous flux in lumens: lm
Select area unit type:  
Enter spherical radius:
Or enter surface area:
   
Illuminance result in lux: lx


Lumens to candela calculator

Calculations of Lumens to lux

There are two methods to calculate the lumens to lux:

Calculation with area in square feet

The illuminance Ev in lux (lx) is equal to 10.76391 times the luminous flux ΦV in lumens (lm) divided by the surface area A in square feet (ft2):

Ev(lx) = 10.76391 × ΦV(lm) / A(ft2)

 

The illuminance Ev in lux (lx) is equal to 10.76391 times the luminous flux ΦV in lumens (lm) divided by 4 times pi times the squared sphere radius r in feet (ft):

Ev(lx) = 10.76391 × ΦV(lm) / (4⋅π⋅r(ft)2)

Calculation with area in square meters

The illuminance Ev in lux (lx) is equal to the luminous flux ΦV in lumens (lm) divided by the surface area A in square meters (m2):

Ev(lx) = ΦV(lm) / A(m2)

 

The illuminance Ev in lux (lx) is equal to the luminous flux ΦV in lumens (lm) divided by 4 times pi times the squared sphere radius r in meters (m):

Ev(lx) = ΦV(lm) / (4⋅π⋅2(m2))