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## How are LED lights calculated?

To determine the needed lumens, you will need to multiply your room square footage by your room foot-candle requirement. For example, a 100 square foot living room, which needs 10-20 foot-candles, will need 1,000-2,000 lumens. A 100 square foot dining room, which needs 30-40 foot-candles, will need 3,000-4,000 lumens.

## How do you calculate the resistance of an LED?

We’ll use the following formula to determine the resistor value: Resistor = (Battery Voltage – LED voltage) / desired LED current. For a typical white LED that requires 10mA, powered by 12V the values are: (12-3.4)/. 010=860 ohms. To use several LEDs in parallel, sum the current values.

**How do you calculate lighting requirements?**

Multiply width of room x length of room x 1.5 = amount of total minimum wattage needed (assuming an eight foot ceiling). Divide by 60 to get the number of 60-watt equivalent bulbs required. Then, add up the wattage in each bulb in each fixture to figure out how many light fixtures are needed.

**What size resistor do I need for LED?**

LEDs typically require 10 to 20mA, the datasheet for the LED will detail this along with the forward voltage drop. For example an ultra bright blue LED with a 9V battery has a forward voltage of 3.2V and typical current of 20mA. So the resistor needs to be 290 ohms or as close as is available.

### What voltage do LED lights use?

Typically, the forward voltage of an LED is between 1.8 and 3.3 volts. It varies by the color of the LED. A red LED typically drops around 1.7 to 2.0 volts, but since both voltage drop and light frequency increase with band gap, a blue LED may drop around 3 to 3.3 volts.

### What does 5000 lumens mean?

For the average living room of 250 square feet, you’ll need 5,000 lumens as your primary light source, which is equivalent to five 100 watt light bulbs, five 23 watt light bulbs, or eight 10 watt light bulbs.

**How is LED voltage calculated?**

Calculating LED Power To calculate an LED’s power use, simply multiply the LED’s voltage (in volts) by the LED’s current (in amperes). The result, measured in watts, is the amount of power your LEDs use. For example, if your LED has a voltage of 3.6 and a current of 20 milliamperes, it will use 72 milliwatts of power.

**Can I run 5V LED on 12V?**

1 Answer. Putting two in series is not going to work, since you’d then have to interface the serial data line. You could however use a small DC-DC (such as the many LM2596 based) to convert 12V down to 5V. It would also reduce the current requirements in the wiring.

#### What lumens do I need?

As a handy rule of thumb, a sitting room or bedroom will generally require around 10-20 lumens per square foot, while a bathroom or kitchen will need a stronger level of lighting, at around 70-80 lumens per square foot. To work out the lumens you need, simply multiply the square footage of the room by this figure.

#### What happens if you don’t use a resistor with an LED?

When hooking up an LED, you are always supposed to use a current-limiting resistor to protect the LED from the full voltage. If you hook the LED up directly to the 5 volts without a resistor, the LED will be over-driven, it will be very bright for a while, and then it will burn out.

**Do 12v LEDs need resistors?**

LEDs can be ran off multiple voltages, but a series resistor is required to limit the current in the circuit. Too much current in an LED will destroy the device. As with all diodes, LED’s will only allow current to flow in the direction from the anode to the cathode.

**Will higher voltage make LED brighter?**

Adjusting the voltage lower or higher will change the brightness, but only because it also changes the current- higher voltage means the current will increase in an LED.

## How does an LED lighting layout calculator work?

An Indoor LED Lighting Layout Calculator is a software tool that allows you to enter room dimensions, fixture count and approximate foot candles you are hoping for and then calculates the number of fixtures you might need. The calculation to find the correct number of lights starts with understanding how bright you want the space to be.

## How do you calculate the number of lights in a room?

The calculation to find the correct number of lights starts with understanding how bright you want the space to be. This is a measurement called Foot Candles. Once you know how many foot candles you want or need, then you can add / subtract lights from the space until it produces the foot candles you are looking for.

**Is there a way to calculate CO2 savings for LED bulbs?**

If you want to work out the lumens brightness conversion for LED or CFL bulbs, give our lumens to watts or watts to lumens converters a try. The LED Saving Calculator produces a calculation for CO2 emissions.

**What do you need to know about led current rating?**

LED current rating (mA): The amount of current needed, in milliamps (mA), for the LED to light properly. This value is usually provided by the manufacturer Also known as forward current If you are not sure of your LED current rating use 20mA for common LEDs Number of LEDs: The number of LEDs in your array Output: Wiring Diagram Schematic