Resistor Plus

Resistor Calculator is the essential tool for electronics engineers, hobbyists, makers, and students. Instantly decode resistor color bands, calculate circuit values, and look up standard resistor values — all in one app.

RESISTOR COLOR CODE CALCULATOR • Support for 4-band, 5-band, and 6-band resistors • Tap color bands on a realistic resistor graphic to read values instantly • View resistance, tolerance, min/max range, and temperature coefficient • Intuitive color picker with all standard EIA color codes

REVERSE LOOKUP • Enter a resistance value and get the matching color band combination • Find the closest standard value from E-series tables • Perfect for designing circuits and selecting components

SERIES & PARALLEL CALCULATOR • Calculate total resistance for resistors in series or parallel • Add unlimited resistors with engineering notation input (e.g. 4.7k, 2.2M) • See live results with formula reference

VOLTAGE DIVIDER • Solve for output voltage (Vout) or unknown resistor (R2) • Interactive circuit diagram updates in real time • Supports engineering notation for quick input

E-SERIES REFERENCE LIBRARY • Browse standard resistor values from E12, E24, E48, E96, and E192 series • Search and filter values instantly • Tap to copy any value to clipboard

DESIGNED FOR ENGINEERS • Clean, distraction-free interface • Works on iPhone and iPad • No ads, no subscriptions, no internet required • Haptic feedback for a responsive experience

Whether you are building your first LED circuit or designing professional PCBs, Resistor Calculator Pro gives you fast, accurate answers right on your device. Download now and keep the most useful resistor tool in your pocket.

Resistor Parameters: Band Digit Black - 0 Brown - 1 Red - 2 Orange - 3 Yellow - 4 Green - 5 Blue - 6 Violet - 7 Grey - 8 White - 9

Band Multiplier Black × 1 Ω Brown × 10 Ω Red × 100 Ω Orange × 1 kΩ Yellow × 10 kΩ Green × 100 kΩ Blue × 1 MΩ Violet × 10 MΩ Gold × 0.1 Ω Silver × 0.01 Ω

Band Tolerance Brown - 1% Red - 2% Gold - 5% Silver - 10%

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, divide voltages, bias active elements, and terminate transmission lines, among other uses. A resistor opposes the flow of electrical current; the higher the value of the resistor, the more it opposes the current flow. Values are given in ohms.

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