Resistor Calculators

Decode color codes, read SMD markings, combine series & parallel networks, and size power ratings — seven complete tools, all live.

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Pick the four band colors and get the value, tolerance and acceptable range with a live visual.

Precision three-digit color codes with tight tolerances, decoded instantly.

Precision codes including the temperature coefficient (TCR) in ppm/°C.

3-digit, 4-digit and EIA-96 surface-mount markings, with validation and units.

Equivalent resistance for any number of resistors in series (Ω, kΩ, MΩ).

Equivalent resistance for parallel branches, recalculated as you type.

Dissipated power from V, I and R, plus a recommended rating with a safety margin.

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