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Electronics tools
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Fast, accurate calculators for resistors, LEDs, Ohm's law, voltage dividers, and more. Built for engineers, students, and makers.

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Resistor Calculator

Decode or encode resistor color bands. Get resistance, tolerance, E-series info, and practical insights.

Color โ†’ Value Value โ†’ Color 3/4/5 Band SMD Code

Ohm's Law Calculator

Calculate voltage, current, resistance, and power. Visual circuit diagram with real-time updates.

V = IR Power (P) Triangle Helper

LED Calculator

Find the right current-limiting resistor for your LED. Supports series and parallel LED strings.

Series/Parallel Any color LED Resistor value

Voltage Divider

Calculate output voltage for any resistor divider network. Includes loading effect analysis.

R1 / R2 Vout Preview Load Analysis

Reference Charts

E-series tables, color code charts, standard capacitor values, and common component specs.

E12 / E24 / E96 Color Chart Capacitor Values

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Capacitor codes, inductor calc, frequency tools...

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