Resistor Color Code Calculator

Select color bands to decode a resistor's value and tolerance.

Band 1 — digit

Band 2 — digit

Band 3 — multiplier

Band 4 — tolerance

Resistance

1 kΩ

Tolerance±5%

Range950 Ω – 1.05 kΩ

How to read resistor color codes

Resistors use color bands to encode their value. For a 4-band resistor: bands 1 and 2 are the first two significant digits, band 3 is the multiplier (power of 10), and band 4 is tolerance. A 5-band resistor adds a third significant digit before the multiplier for greater precision. The standard color-to-digit mapping runs Black=0 through White=9; Gold and Silver are only used for tolerance (±5% and ±10%).

For related electronics calculations, see Ohm's Law Calculator.

Built and maintained by Meet Shah · Last updated 9 August 2026

What this tool is used for

Reading a resistor's value from its bands.
Checking a resistor you have against the value a circuit needs.
Working out which end of the resistor to read from.
Identifying the tolerance band on a five-band resistor.
Confirming a value before soldering it in.

Frequently Asked Questions

How do I read the bands in the right direction?: The tolerance band is usually gold or silver and sits slightly apart from the rest — put it on the right. If both ends look alike, read from the end where the first band is not gold, silver or black, since none of those is a valid first digit.
What is the difference between 4, 5 and 6 bands?: Four bands give two significant digits, a multiplier and a tolerance. Five add a third digit for precision parts. Six add a temperature coefficient in ppm/°C, which matters only where the resistance must hold across a wide temperature range.
What do gold and silver mean as a multiplier?: They divide rather than multiply: gold is ×0.1 and silver is ×0.01. That is how sub-ohm values are written — a resistor reading brown-black-gold is 1 Ω, not 10.
Why is 220 Ω common but 250 Ω not?: Preferred values. Resistors are made to the E-series — E12 gives 1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2 — spaced so that consecutive values overlap within tolerance. 250 is simply not in the series, so it is not stocked.
How do I read a resistor if I am colour-blind?: You cannot reliably, and roughly one man in twelve is affected. A multimeter across the component is the answer, and it is also the only way to check an aged or scorched part whose bands have discoloured. Surface-mount parts print digits instead for the same reason.

Common errors and gotchas

Reading the bands from the wrong end, which gives a completely different value.
Confusing 4-band and 5-band layouts, where the multiplier position moves.
Misidentifying brown and red, or blue and violet, under poor lighting.
Ignoring the tolerance, which matters in a precision circuit.
Assuming the marked value is the measured one, which tolerance explicitly allows to differ.