How do I tell 4-band from 5-band?

Count colored bands. 4-band has 4 bands total; 5-band has 5. 5-band is used for precision resistors (±0.1% to ±2% tolerance); 4-band for everyday ±5%-±20% parts.

What is the temperature coefficient?

How much the resistance drifts per degree Celsius. 100 ppm/°C means a 100 Ω resistor changes by 0.01 Ω per °C (or 1 Ω per 100 °C). Precision applications (instrumentation, RF, calibration) demand low TC.

Why no gold/silver multiplier on the digit bands?

Gold and silver are RESERVED for the multiplier and tolerance bands; they never appear in the digit positions. This makes it unambiguous which direction to read.

IEC 60062:2016 — Marking codes for resistors and capacitors. EIA-RS-279 (precursor US standard). Horowitz & Hill "The Art of Electronics" 3rd ed Appendix.

How do I tell 4-band from 5-band?

Count colored bands. 4-band has 4 bands total; 5-band has 5. 5-band is used for precision resistors (±0.1% to ±2% tolerance); 4-band for everyday ±5%-±20% parts.

What is the temperature coefficient?

How much the resistance drifts per degree Celsius. 100 ppm/°C means a 100 Ω resistor changes by 0.01 Ω per °C (or 1 Ω per 100 °C). Precision applications (instrumentation, RF, calibration) demand low TC.

Why no gold/silver multiplier on the digit bands?

Gold and silver are RESERVED for the multiplier and tolerance bands; they never appear in the digit positions. This makes it unambiguous which direction to read.

IEC 60062:2016 — Marking codes for resistors and capacitors. EIA-RS-279 (precursor US standard). Horowitz & Hill "The Art of Electronics" 3rd ed Appendix.

Resistor Color Code Calculator (4/5/6 band)

Decode resistance, tolerance, and (6-band) temperature coefficient from IEC 60062 color rings.

Inputs

Number of bands

Band 1 (digit)

Band 2 (digit)

Band 3 (digit)

Multiplier band

Tolerance band

Temperature coefficient band (6-band only)

Result

Resistance

1.1000 kΩ

±5% tolerance → 1.0450 kΩ … 1.1550 kΩ.

Band 1 (digit)brown = 1
Band 2 (digit)brown = 1
Band 3 (multiplier)red = ×100
Band 4 (tolerance)gold = ±5%
Nominal value1.1000 kΩ
Tolerance band±5%
Minimum (Rnom − Δ)1.0450 kΩ
Maximum (Rnom + Δ)1.1550 kΩ

Step-by-step

Digits = 11 = 11; × multiplier 100 = 1100 Ω.
Tolerance ±5% gives range 1.0450 kΩ to 1.1550 kΩ.

How to use this calculator

Identify the side with the closer-spaced band group — read FROM THAT END.
Pick the number of bands (4/5/6) — most consumer parts are 4-band.
Select each band's color from the dropdown.
For 6-band parts: the last band (most-spaced from the others) is the temperature coefficient.

About this calculator

IEC 60062 standardises the color-band coding used on through-hole resistors worldwide. 4-band (the common consumer-grade standard): two significant digits + multiplier + tolerance. 5-band (precision parts, ±0.1%-±2%): three significant digits for better precision. 6-band (very precise / temperature-stable): adds a temperature-coefficient band in ppm/°C. The IEC color sequence — black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9 — is the same first ten as the standard rainbow shifted slightly and is universal across electronics. Mnemonic ("Bad Boys..." or "Better Be Right Or Your Great Big Venture Goes West"). Surface-mount resistors use numeric codes instead (3 or 4 digit + EIA-96 alpha-numeric). This calculator covers through-hole only.