LED Resistor Calculator

Single led - Leds in series - Leds in parallel

Single led:
	Maximum Supply Voltage (V_max)This is the maximum voltage which the led circuit and resistor will ever be exposed to. Note that most 12 volt systems are nominally 12 volts, but in practice often are actually 13 volts, 14 volts or even 14.5+ volts. This oversight is the primary cause of premature led failure. If the actual voltage applied to your circuit exceeds this number, the led and/or resistor would fail prematurely, or possibly instantly. To be safe, be sure to use the maximum expected voltage. VOLTS Forward Voltage (V_f)This is the maximum voltage which the led can safely operate at if there was no resistance. "Forward" refers to the voltage being applied to the circuit forward of the resistor, rather than thru the resistor. This is usally a low voltage, like 1.8-4.0 volts. If a higher voltage is applied directly to the led without passing thru a resistor, the led would fail prematurely, or possibly instantly. VOLTS Maximum LED Current (l_max)This is the maximum current which the led is rated to be able to be driven at. With higher powered leds, you must also assure that you have suficent cooling to allow the led to survive at peak rated current. If the maximum rated current, or maximum safe operating temperature (junction temperature) of the led is exceeded, the led would fail prematurely, or possibly instantly. MILLIAMPS Resistor Value (R)This is the resistor value which will set the current thru the circuit exactly at the value of the Maximum Led Current value (Imax) when the Maximum Supply Voltage (Vmax) is applied to the circuit. OHMS Nearest Higher Resistor (10%, E12) AvailableThis is the resistor value which is the next higher of the commmon E12 (10%) resistors available. These resistors come in the following sizes: (100,120,150,180,220,270,330,390,470,560,680,820 ohm). By choosing the next higher value resistor the result will be a dimmer led, but less likelihood of premature failure. Choosing the next lower value resistor will result in a brigher led, but higher risk of premature failure. OHMS Minimum Resistor Wattage (W_min)This is the minimum acceptable wattage rating for the resistor to be used. Using a resistor with a higher wattage rating is always better, and will result in both the resistor and led staying cooler and lasting longer. The downside of choosing a resistor which is rated too high in wattage is that resistors which are rated at higher wattages are also larger in size. Choosing a resistor that is close to, or below the Minimum Resistor Wattage value will result in the resistor failing and could also cause a fire, or burn up the circuity and led. WATTS (Or Greater) Recommended Resistor Wattage (W_rec)This is a recommended wattage rating for the resistor to be used. Using a resistor with a higher wattage rating is always better, and will result in both the resistor and led staying cooler and lasting longer. The downside of choosing a resistor which is rated too high in wattage is that resistors which are rated at higher wattages are also larger in size. Choosing a resistor that is close to, or below the Minimum Resistor Wattage value will result in the resistor failing and could also cause a fire, or burn up the circuity and led. WATTS (Or Greater)
Leds in series:
	Maximum Supply Voltage (V_max)This is the maximum voltage which the led circuit and resistor will ever be exposed to. Note that most 12 volt systems are nominally 12 volts, but in practice often are actually 13 volts, 14 volts or even 14.5+ volts. This oversight is the primary cause of premature led failure. If the actual voltage applied to your circuit exceeds this number, the led and/or resistor would fail prematurely, or possibly instantly. To be safe, be sure to use the maximum expected voltage. VOLTS Forward Voltage (V_f)This is the maximum voltage which each of the the leds alone can safely operate at if there was no resistance. "Forward" refers to the voltage being applied to the circuit forward of the resistor, rather than thru the resistor. When you have more than one led, you must use the lowest value of the led with the lowest value so that it will not be overloaded, or if the Forward Voltage of each of leds on the same circuit are mot matched closely, then they should be on seperate circuits with their own resistor. This value is usally a low voltage, like 1.8-4.0 volts. If a higher voltage is applied directly to the led without passing thru a resistor, the led would fail prematurely, or possibly instantly. If one or more of the leds connected has a lower Forward Voltage than is used in the calculation, then that led will be vulnerable to premature failure. VOLTS Maximum LED Current (l_max)This is the maximum current which the led is rated to be able to be driven at. With higher powered leds, you must also assure that you have suficent cooling to allow the led to survive at peak rated current. If the maximum rated current, or maximum safe operating temperature (junction temperature) of any of the leds in the circuit is exceeded, the led would fail prematurely, or possibly instantly. MILLIAMPS Number Of Leds ConnectedEnter the total number of leds to be connected to this resistor. Resistor Value (R)This is the resistor value which will set the current thru the circuit exactly at the value of the Maximum Led Current value (Imax) when the Maximum Supply Voltage (Vmax) is applied to the circuit. OHMS Nearest Higher Resistor (10%, E12) AvailableThis is the resistor value which is the next higher of the commmon E12 (10%) resistors available. These resistors come in the following sizes: (100,120,150,180,220,270,330,390,470,560,680,820 ohm). By choosing the next higher value resistor the result will be a dimmer led, but less likelihood of premature failure. Choosing the next lower value resistor will result in a brigher led, but higher risk of premature failure. OHMS Minimum Resistor Wattage (W_min)This is the minimum acceptable wattage rating for the resistor to be used. Using a resistor with a higher wattage rating is always better, and will result in both the resistor and led staying cooler and lasting longer. The downside of choosing a resistor which is rated too high in wattage is that resistors which are rated at higher wattages are also larger in size. Choosing a resistor that is close to, or below the Minimum Resistor Wattage value will result in the resistor failing and could also cause a fire, or burn up the circuity and led. WATTS (Or Greater) Recommended Resistor Wattage (W_rec)This is a recommended wattage rating for the resistor to be used. Using a resistor with a higher wattage rating is always better, and will result in both the resistor and led staying cooler and lasting longer. The downside of choosing a resistor which is rated too high in wattage is that resistors which are rated at higher wattages are also larger in size. Choosing a resistor that is close to, or below the Minimum Resistor Wattage value will result in the resistor failing and could also cause a fire, or burn up the circuity and led. WATTS (Or Greater)
Leds in parallel:
	Maximum Supply Voltage (V_max)This is the maximum voltage which the led circuit and resistor will ever be exposed to. Note that most 12 volt systems are nominally 12 volts, but in practice often are actually 13 volts, 14 volts or even 14.5+ volts. This oversight is the primary cause of premature led failure. If the actual voltage applied to your circuit exceeds this number, the led and/or resistor would fail prematurely, or possibly instantly. To be safe, be sure to use the maximum expected voltage. VOLTS Forward Voltage (V_f)This is the maximum voltage which each of the the leds alone can safely operate at if there was no resistance. "Forward" refers to the voltage being applied to the circuit forward of the resistor, rather than thru the resistor. When you have more than one led ands you connect in parralel, it is essential that the Forward Voltage of each led in the circuit be identical, or the led with the lower Forward Voltage will be overloaded, or if the Forward Voltage of each of leds on the same circuit are not midentical, then they should be on seperate circuits with their own resistor. This value is usally a low voltage, like 1.8-4.0 volts. If a higher voltage is applied directly to the led without passing thru a resistor, the led would fail prematurely, or possibly instantly. If one or more of the leds connected has a lower Forward Voltage than is used in the calculation, then that led will be vulnerable to premature failure. VOLTS Maximum LED Current (l_max)This is the maximum current which the led is rated to be able to be driven at. With higher powered leds, you must also assure that you have suficent cooling to allow the led to survive at peak rated current. If the maximum rated current, or maximum safe operating temperature (junction temperature) of any of the leds in the circuit is exceeded, the led would fail prematurely, or possibly instantly. MILLIAMPS Number Of Leds ConnectedEnter the number of leds you are connecting to the circuit. Resistor Value (R)This is the resistor value which will set the current thru the circuit exactly at the value of the Maximum Led Current value (Imax) when the Maximum Supply Voltage (Vmax) is applied to the circuit. OHMS Nearest Higher Resistor (10%, E12) AvailableThis is the resistor value which is the next higher of the commmon E12 (10%) resistors available. These resistors come in the following sizes: (100,120,150,180,220,270,330,390,470,560,680,820 ohm). By choosing the next higher value resistor the result will be a dimmer led, but less likelihood of premature failure. Choosing the next lower value resistor will result in a brigher led, but higher risk of premature failure. OHMS Minimum Resistor Wattage (W_min)This is the minimum acceptable wattage rating for the resistor to be used. Using a resistor with a higher wattage rating is always better, and will result in both the resistor and led staying cooler and lasting longer. The downside of choosing a resistor which is rated too high in wattage is that resistors which are rated at higher wattages are also larger in size. Choosing a resistor that is close to, or below the Minimum Resistor Wattage value will result in the resistor failing and could also cause a fire, or burn up the circuity and led. WATTS (Or Greater) Recommended Resistor Wattage (W_rec)This is a recommended wattage rating for the resistor to be used. Using a resistor with a higher wattage rating is always better, and will result in both the resistor and led staying cooler and lasting longer. The downside of choosing a resistor which is rated too high in wattage is that resistors which are rated at higher wattages are also larger in size. Choosing a resistor that is close to, or below the Minimum Resistor Wattage value will result in the resistor failing and could also cause a fire, or burn up the circuity and led. WATTS (Or Greater)

Links
Automotive Replacement Light Bulbs:	Other Auto & Motorcycle Lighting:	Low Voltage Utility Lights & Fixtures	Truck 4X4 RV & Trailer Lighting	Household, Commercial & Industrial Lighting	Other Products	Reference:
1156 1157 1142 2357 7507 7225 Bayonet Tail-Brake Turn Signal Back-Up	LED Light Fixtures & Strobes	LED Light Fixtures & Strobes	Semi, Truck & Truck Trailer LEDS	Lights For the Home, Yard & Garden	LED Windshield Washer & Mirror Turn Signal Indicators	Specs
3157 3156 3457 4157 3057 Wedge Tail-Brake-Turn Signal & Back-Up Bulbs	Light Bright NEON Glow Wire	LED Strips, Led Strings. Led Bars	Clearance and Side Marker Lights	LED Strips, Led Strings. Led Bars	LED Flashers, Protectors, Load Equalizers Turn Signal Fix	Cross Reference
7443 7440 Wedge Tail-Brake-Turn Signal & Back-Up Bulbs	LED Neo-Neon Flexible NEON Light Tubing	LED Strips Connectors, Adapters & Mounting Hardware	Tail Stop Work & Turn Signal Lights	MR11, MR16 GU10 Bulbs	Electrical Contacts, Sockets, Connectors & Fuses	Technical Data
194 168 2825 W5W Wedge Side Marker License Plate & Interior Bulbs	HID Headlight Fog Light & Reverse Light Systems	Control Modules & Power Supplies	Indicator Lights	LED Light Fixtures for the Home & RV	Led Controllers, Flashing Modules, Braker Modules & Dimmers	Bulb Dimensions
37 74 Gauge & Instrument Panel & Neo-Wedge Bulbs	Daytime Running Light (DRL) Kits and Fog Light Systems	Overhead & Under Cabinet Lighting _ Trucks - Boats & RV's	Overhead Cab Lighting	Track Lights	Miniature Train Bulbs & Parts	General Bulb Information
3022 3122 561 578 6418 6411 Festoon Dome Bulbs	LED Screw Mount Indicator & Accent Lights	LED Light Fixtures for the Home Boat & RV	Daytime Running Light (DRL) Kits and Fog Light Systems	LED Neo-Neon Flexible NEON Light Tubing	Universal Programmable Remote Controllers & Switches for Garage Door Openers	Application Charts
Ba9s, E10, Ba7s, Small Ba15s and Bay15d Bayonet Bulbs	LED & Neon Light Tubes & Underbody Light Kits	LED Bike, Go Ped, Motorcycle, ATV, Boat and RV Light Fixtures	Connectors & Grommets	LVD Electromagnetic Induction Bulbs	Discrete Raw Leds, Resistors & Components	Bases & Filaments
< 906 921 Wedge Stop & Interior Bulbs	LED Windshield Washer & Mirror Turn Signal Indicators	LED Screw Mount Indicator & Accent Lights			Power Inverters - Power Supplies - Power Adapters	Led Resistor Calculations
Headlights DRL & Foglights	Overhead Cab Lighting				LED Flashlights Work Lights & Bulbs	Shipping
HID Systems	Angel Eye Halo Rings for Headlights Tail Lights & Lenses				LED Bike, Go Ped, Motorcycle, ATV, Boat and RV Light Fixtures	Mail Orders
6 Volt Antique - Vintage Bulbs & 24 volt	LED Flashing Dimming & Wig -Wag Modules				Electrical Wire & Shrink Tubing	International Shipping
L1142 1076 1176 Boat & Marine Bulbs	Power Inverters - Power Supplies - Power Adapters				Motorcycle & RV Running Lights, Turn Signals & Indicator Lights	FAQ'S
Dura Chrome Titanium Platinum Silver Vision Bulbs	Switchback Bulbs Two-Color Turn Signal Running Light s				Air Horns	Policies
Xenon Plasma Super Hyper White Bulbs					Vinyl Protective Film for Tinting Headlights, Tail Lights & Lenses	Visual Bulb Finder
G4 T10 2 Pin Bi- Pin					Vinyl 3D Carbon Fiber Decorative Self-Adhesive Film	Lookup Order & Tracking Number
						Sitemap
Canbus Error Free Bulbs BMW Mercedes Audi VW Volvo Dodge 5002S PY24W
Weekly Sale Items	CarInfoTech