LED Series Resistor
Calculate LED Series Resistor instantly with the exact formula and a worked example. Free online calculator — no signup, works on mobile.
LED Series Resistor
Supply, V
LED U, V
I, mA
R
500Ω
More about: LED Series Resistor
What it calculates
The “LED Series Resistor” calculator computes R in Ω from 3 parameters: supply, v, led u, v, i, ma.
Used in design, material estimation, and structural calculations.
Example calculation
With parameters Supply, V = 12, LED U, V = 2, I, mA = 20 the result is 500 Ω.
How to use
- Enter the parameter values — every field above is adjustable with a slider.
- The result and related metrics are calculated automatically as you type.
- Use the additional metrics shown (if any) where needed.
- Copy the result or bookmark the page.