Free Online Engineering Tools

Resistor Color Code Calculator

Decode 3, 4, 5, and 6 band resistors instantly — click the colour bands to read the resistance, tolerance, and temperature coefficient, or switch to reverse mode to find the bands for any resistance value. Includes a live resistor diagram and a complete colour code chart.

🎚️ Number of Bands

🔁 Input Mode

🎨 Select Color Bands

📊 Results

Resistance

1.0 kΩ

Tolerance

±5%

Minimum

950 Ω

Maximum

1.05 kΩ

Nearest E24

1.0 kΩ

📐 Live Resistor Diagram

Resistance = 10 × 100 = 1,000 Ω = 1.0 kΩ
Tolerance = ±5%
💡

Hold the resistor with the grouped bands on the left and the lone tolerance band (often gold/silver) on the right. Read left to right.

🎨 Resistor Color Code Chart (Complete Reference)

ColorDigitMultiplierToleranceTemp. Coeff. (ppm/°C)

Resistor Color Code Calculator: Read Any 3, 4, 5, or 6 Band Resistor

This resistor color code calculator decodes the colored bands printed on through-hole resistors into a resistance value, tolerance, and (for 6-band parts) a temperature coefficient. Click each band's color in the panel above, choose how many bands your resistor has, and the resistance, tolerance, minimum/maximum range, and nearest standard E-series value are computed instantly and drawn on a live resistor diagram. You can also work backwards with Value → Bands mode to find the colors for a target resistance.

Quick Reference: How Many Bands?

BandsLayoutExampleUsed for
3-band2 digits + multiplier (assumed ±20%)Brown-Black-Red = 1 kΩOld / very low precision
4-band2 digits + multiplier + toleranceBrown-Black-Red-Gold = 1 kΩ ±5%Most common general-purpose
5-band3 digits + multiplier + toleranceBrown-Black-Black-Brown-Brown = 1 kΩ ±1%Precision resistors
6-band3 digits + multiplier + tolerance + TCR…-Brown (100 ppm/°C)High-precision / temperature-stable

How to Read a Resistor Color Code

Every resistor encodes its value in a sequence of colored bands. The exact meaning depends on the band's position:

4-band: [Digit 1][Digit 2] × [Multiplier] ± [Tolerance]

5-band: [Digit 1][Digit 2][Digit 3] × [Multiplier] ± [Tolerance]

6-band: [Digit 1][Digit 2][Digit 3] × [Multiplier] ± [Tolerance], [Temp. Coefficient]

Read from the end where the bands are grouped most closely together. The tolerance band (commonly gold or silver) sits slightly apart on the opposite end and is read last.

The Resistor Color Code Chart

Each color maps to a digit, a multiplier (power of ten), a tolerance percentage, and a temperature coefficient. This is the universal key used by the calculator above:

ColorDigitMultiplierToleranceTemp. Coeff.
Black0×1250 ppm/°C
Brown1×10±1%100 ppm/°C
Red2×100±2%50 ppm/°C
Orange3×1,00015 ppm/°C
Yellow4×10,00025 ppm/°C
Green5×100,000±0.5%20 ppm/°C
Blue6×1,000,000±0.25%10 ppm/°C
Violet7×10,000,000±0.1%5 ppm/°C
Grey8×100,000,000±0.05%1 ppm/°C
White9×1,000,000,000
Gold×0.1±5%
Silver×0.01±10%
None±20%

Worked Examples

Example 1 — 4-band: Brown, Black, Red, Gold

Digits: 1, 0 → "10". Multiplier: red = ×100. Tolerance: gold = ±5%.

10 × 100 = 1,000 Ω = 1 kΩ ±5%

Example 2 — 4-band: Yellow, Violet, Orange, Gold

Digits: 4, 7 → "47". Multiplier: orange = ×1,000. Tolerance: gold = ±5%.

47 × 1,000 = 47,000 Ω = 47 kΩ ±5%

Example 3 — 5-band: Brown, Green, Black, Brown, Brown

Digits: 1, 5, 0 → "150". Multiplier: brown = ×10. Tolerance: brown = ±1%.

150 × 10 = 1,500 Ω = 1.5 kΩ ±1%

Common Resistor Values and Their Color Codes

Resistance4-Band Colors (±5%)
10 ΩBrown, Black, Black, Gold
100 ΩBrown, Black, Brown, Gold
220 ΩRed, Red, Brown, Gold
330 ΩOrange, Orange, Brown, Gold
470 ΩYellow, Violet, Brown, Gold
1 kΩBrown, Black, Red, Gold
2.2 kΩRed, Red, Red, Gold
4.7 kΩYellow, Violet, Red, Gold
10 kΩBrown, Black, Orange, Gold
47 kΩYellow, Violet, Orange, Gold
100 kΩBrown, Black, Yellow, Gold
1 MΩBrown, Black, Green, Gold

What Is Tolerance?

Tolerance is the maximum percentage by which the actual resistance may differ from the nominal value. A 1 kΩ resistor with ±5% tolerance is guaranteed to measure between 950 Ω and 1,050 Ω. Tighter tolerance bands (±1%, ±0.1%) cost more and are used in precision analog circuits, filters, and measurement equipment, while ±5% is fine for pull-ups, current limiting, and general use.

What Is the Temperature Coefficient (6th Band)?

On 6-band resistors the final band gives the temperature coefficient of resistance (TCR) in parts per million per degree Celsius (ppm/°C). A 100 ppm/°C resistor changes by 0.01% per degree. Lower TCR means the resistance stays more stable as the part heats up — important in precision references, instrumentation, and circuits exposed to wide temperature swings.

E-Series Preferred Values

Resistors are manufactured in standardized "preferred values" called E-series, spaced so that tolerance bands cover the whole range with minimal overlap:

  • E6 (±20%): 10, 15, 22, 33, 47, 68
  • E12 (±10%): 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82
  • E24 (±5%): adds 11, 13, 16, 20, 24, 30, 36, 43, 51, 62, 75, 91
  • E96 (±1%): 96 values per decade for precision resistors

The calculator shows the nearest E24 value so you can pick a real, purchasable part.

Frequently Asked Questions

What color is a 1k ohm resistor?

A 1 kΩ 4-band resistor is Brown-Black-Red with a gold tolerance band (10 × 100 = 1,000 Ω ±5%).

What color is a 10k ohm resistor?

Brown-Black-Orange-Gold (10 × 1,000 = 10,000 Ω ±5%).

What color is a 220 ohm resistor?

Red-Red-Brown-Gold (22 × 10 = 220 Ω ±5%).

Which end do I read first?

Start at the end with the bands grouped close together. The lone band on the opposite end (often gold or silver, with a wider gap) is the tolerance band, read last.

What does a gold band mean?

As the tolerance band it means ±5%; as a multiplier band it means ×0.1. Silver is ±10% tolerance or ×0.01 multiplier.

Why do some resistors have no tolerance band?

A 3-band resistor (or a 4-band with the 4th band absent) implies ±20% tolerance. These are old or very low-precision parts.

Are SMD resistors color coded?

No. Surface-mount resistors use a printed numeric code (e.g., "472" = 4,700 Ω, or the EIA-96 code) instead of colored bands.

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