Resistor Color Code Calculator

Two directions, one page. Pick the colours on a real resistor and see its resistance, tolerance, and (for 6-band) temperature coefficient — or type a target resistance and see the colour bands you'd buy across the E6 / E12 / E24 / E48 / E96 series. Pure client-side, no upload.

Bands
Resistance — —
Tolerance — —

Pick four colours to start.

How the colour code works

Most through-hole resistors have four coloured stripes that together encode the resistance:

  • Bands 1 and 2 are the first and second significant digits (0-9).
  • Band 3 (multiplier) tells you how many zeros to add — except for gold (×0.1) and silver (×0.01) which are used for very small resistors.
  • Band 4 (tolerance) says how far the real value may deviate from the marked value. Gold = ±5%, the most common 4-band rating. Silver = ±10%, no band = ±20%.

A 5-band resistor has three significant digits plus a multiplier and tolerance — used when the value needs more precision (E96 series, ±1% or tighter).

A 6-band resistor adds a temperature-coefficient band (ppm/°C), telling you how much the value drifts as the resistor heats up. Important for precision analog circuits.

The E-series ladders (E6, E12, E24, E48, E96) list every resistance value you'll find in stock at your electronics supplier. Each series has a fixed tolerance ladder: E12 = ±10%, E24 = ±5%, E96 = ±1%.

Numbers on this page are computed locally. Nothing is uploaded.