Quick answer: An orange LED can have a dominant wavelength of 600–610 nm; Dialight's orange example has a typical forward voltage of 2 V at 20 mA. For a bare indicator LED, use current limiting rather than connecting it directly to a supply. The wavelength and voltage come from the Dialight orange LED datasheet; according to Wikipedia's LED electrical explanation, indicator LEDs usually use a series resistor.
This guide covers colour selection and low-voltage calculations for a bare orange indicator LED. It separates a named component's specifications from a calculator preset, so you can see which numbers describe the part and which are assumptions for an example. For other lighting calculations, start at the LEDask calculator hub.
What wavelength is an orange LED?
Use the component's wavelength range to compare colours. The Dialight orange AlInGaP part, 598-8030-107F, specifies a dominant wavelength from 600 to 610 nm at a test current of 20 mA, without listing a typical wavelength. Dialight datasheet
The table below compares neighbouring colours within that same product family. According to Dialight, orange falls between its yellow and red-orange entries; these are the maker's ranges, not a universal naming rule.
| Colour in the Dialight family | Dominant wavelength range | Source |
|---|---|---|
| Yellow, shorter-wavelength entry | 583–590 nm | Dialight |
| Yellow, longer-wavelength entry | 590–595 nm | Dialight |
| Orange | 600–610 nm | Dialight |
| Red-orange | 620–630 nm | Dialight |
For a broader reference, Wikipedia's colour table places orange above 590 nm and below 610 nm. Its illustrated LED pack caption gives orange as 600–610 nm, agreeing with the Dialight example. These descriptions serve different purposes: a general colour table is useful for orientation, while a component range is the useful purchase specification. Wikipedia LED colour references
Is orange the same as amber?
Do not assume an amber label identifies the same wavelength as an orange label. According to ENERGY STAR, common LED colours include amber, red, green and blue. That naming list does not give an amber wavelength range or establish that amber and orange are interchangeable. ENERGY STAR LED guide
For a replacement indicator, compare the stated wavelength with the part being replaced. A colour name alone leaves that comparison unresolved. If a listing says only “amber,” it does not provide enough information to place it in the orange row of the table above.
What voltage and current does an orange LED need?
Forward voltage describes the drop across the LED at a stated current; it is not a complete power-supply specification. The Dialight orange example lists a minimum of 1.7 V, a typical value of 2 V and a maximum of 2.4 V at 20 mA. Use that spread when assessing a circuit instead of treating the typical value as exact. Dialight electrical characteristics
According to Dialight, the same part's absolute maximum ratings include 25 mA forward current, 60 mW power dissipation and an operating temperature range of −30 to +85 °C. These are limits for this component, not a suggested operating point for every orange LED. Dialight absolute maximum ratings
According to Wikipedia, LED current rises exponentially with applied voltage, so a small voltage change can produce a large current change. Its electrical explanation calls for a current-regulated supply, usually a series resistor for indicator LEDs. That is why choosing a supply voltage alone does not finish the circuit calculation. Wikipedia LED electrical characteristics
What resistor should I use with an orange LED?
For the assumed circuit below, the calculator selects 150 Ω and a 125 mW resistor rating. Use the LED resistor calculator to change the supply, forward voltage, target current or number of LEDs. Its orange preset uses 2.1 V and 20 mA as the calculator's planning figures, rather than measurements of your component.
Worked example: an assumed single-LED circuit
Assumed inputs: a 5 V DC supply, one LED, a 2.1 V forward drop and a 20 mA target current, with the latter values taken from the calculator's orange preset. Assume the supply and LED drop stay fixed for this calculation.
The calculator uses R = (supply voltage − LED count × forward voltage) ÷ current in amperes:
- Convert current: I = 20 ÷ 1,000 = 0.020 A.
- Total LED drop: 1 × 2.1 = 2.1 V.
- Voltage across the resistor: 5 − 2.1 = 2.9 V.
- Calculated resistance: R = 2.9 ÷ 0.020 = 145 Ω.
- The calculator selects the nearest value from its E24 list: 150 Ω.
- Recalculate current: I = 2.9 ÷ 150 = 0.019333… A; multiplying by 1,000 gives 19.333… mA, displayed as 19.3 mA.
- Resistor power: P = I² × R = (2.9 ÷ 150)² × 150 = 8.41 ÷ 150 = 0.056066… W, approximately 0.056 W.
- Apply the calculator's planning figure of a 2× power margin: 0.056066… × 2 = 0.112133… W. Its next listed rating is 0.125 W = 125 mW = 1/8 W.
The recalculated current and resistor dissipation use the selected resistance, not the unrounded resistance. Keeping that distinction makes the power calculation agree with the calculator's result.
Worked comparison: an assumed lower forward drop
Keep the assumed 5 V supply, one LED and 150 Ω resistor, but assume a 1.7 V forward drop. This assumed drop matches the minimum listed for the Dialight example at its stated test current; it is not a prediction of an individual LED's operating voltage. Dialight datasheet
- Resistor voltage = 5 − (1 × 1.7) = 3.3 V.
- Current = 3.3 ÷ 150 = 0.022 A; 0.022 × 1,000 = 22 mA.
- Resistor power = 0.022² × 150 = 0.000484 × 150 = 0.0726 W.
- Calculator power margin = 0.0726 × 2 = 0.1452 W, so its selected rating becomes 0.25 W.
The same resistor produces a different calculated current when the assumed LED drop changes. Repeating this calculation with your chosen component's values is more useful than copying a resistor value without its assumptions.
Where are orange LEDs useful, and how do I choose one?
An indicator is a practical use to consider. According to ENERGY STAR, coloured LEDs are widely used as signal lights and indicator lights, including computer power-button indicators. That supports an indicator application; it does not establish a health benefit from orange light. ENERGY STAR LED applications
For a low-voltage indicator project, make the selection in this order:
- Choose the colour using the stated wavelength range.
- Identify the component's forward voltage at the intended current.
- Enter the supply voltage and LED count into the resistor calculation.
- Recalculate current and dissipation using the selected resistor, as shown above.
- Compare the result with the component's current and power limits.
This process gives each input a purpose: wavelength answers the colour question, while voltage and current determine the resistor calculation.
FAQ
What wavelength should I look for in an orange LED?
The Dialight example specifies 600–610 nm at 20 mA. Use this as a concrete reference for orange, while matching the range stated for the component you select. Dialight datasheet
Does every orange LED have the same forward voltage?
No fixed value should be inferred from the colour name: even the Dialight example lists 1.7 V minimum, 2 V typical and 2.4 V maximum at 20 mA. Dialight datasheet
Can I connect a bare orange LED directly to a supply?
Use current limiting. According to Wikipedia, LED current rises exponentially with voltage, and indicator LEDs usually use a series resistor. Wikipedia LED electrical characteristics
Is the maximum current the current I should target?
Treat it as a limit, not an instruction to operate there. According to Dialight, its orange example has a 25 mA absolute maximum forward current, while the listed wavelength and voltage characteristics use a 20 mA test current. Dialight datasheet
Will an amber LED match an orange replacement?
The colour names alone do not settle that. ENERGY STAR names amber among common LED colours without specifying its wavelength, so compare the replacement's wavelength specification with the original part. ENERGY STAR LED guide
Jack Shi
Founder & editor, LEDaskJack Shi builds and writes LEDask, an independent LED-lighting tools project operated by clooms. He designs the calculators, checks their formulas and reference values against published engineering data, and writes the guides across the site.
