Mike Holt Basc Math
Light guides formulas
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Lighting-Calculation-Formulas
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Formulas
How Much Light Do I Need?
Glad you asked. There’s actually a proven formula for calculating the
proper amount of general light (usually expressed as the number of
watts) you should have in each room or area of your home . . . and
it’s not difficult, just some basic arithmetic. Multiply the length
times the width of the room. Then, multiply that number times 1.5.
That gives you the amount of wattage you need to light the room
properly for general illumination.
Example: A room is 12 ft. x 16 ft. (12 x 16 = 192). Then multiply 192
x 1.5 = 288 watts. That means an 8-light chandelier using 40-watt
bulbs would give 320 watts, which is even more light than needed.
