Supply voltage Vs, LED forward voltage Vf, and desired If in mA—ballast resistor (Ω) and resistor power (W).
It is a browser-side helper for quick estimates related to LED Series Resistor Calculator. Read each field label and the disclaimer on the page.
Educational / illustrative only. Real-world fees, taxes, rounding, calendars, and product rules are not fully modeled.
Nothing is uploaded; calculations run locally in your browser session.
No. Use qualified professionals and official sources when stakes are high.
Different formulas, rounding, assumptions, or input definitions—compare assumptions carefully.
Inputs stay on your device unless your browser or extensions do otherwise.