Resistor colour code calculator

Q: How do you read a 4-band resistor colour code?

The first two bands are digits, the third is the multiplier and the fourth the tolerance. The digits run black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Yellow, violet, red, gold therefore reads 47 × 10² = 4,700 Ω, with gold meaning ±5%.

Q: Which end of a resistor do you start reading from?

Start from the end away from the gold or silver band. Gold and silver have no digit value in IEC 60062; they only appear as a multiplier (×0.1 and ×0.01) or a tolerance (±5% and ±10%). The first band usually sits closer to its lead, and the tolerance band is often spaced apart from the others.

Q: What is the difference between 4, 5 and 6-band resistors?

A 4-band resistor carries two significant digits, enough for the E6 to E24 values used for ±5% to ±20% parts. A 5-band resistor carries three digits for the E48 to E192 values of ±2% and tighter parts: brown, black, black, red, brown is 100 × 10² Ω = 10 kΩ ±1%. A 6-band resistor adds a temperature-coefficient band.

Q: What does the temperature coefficient band mean?

It gives the resistance drift per kelvin in parts per million: brown 100 ppm/K, red 50, yellow 25, green 20, orange 15, blue 10, violet 5 and grey 1. A 3.3 kΩ resistor with a red band changes by 3,300 × 50 × 10⁻⁶ = 0.165 Ω per degree, about 4.1 Ω over a 25 °C rise.

Q: What if a resistor has only three bands?

A missing tolerance band means ±20%. Brown, black, orange with no fourth band is 10 kΩ, and any value from 8 kΩ to 12 kΩ is within specification. Such parts come from the E6 series (1.0, 1.5, 2.2, 3.3, 4.7, 6.8), whose steps of about 47% suit the wide tolerance.

Q: Quelle est la précision de « Resistor colour code calculator » ?

La précision dépend de vos données et des hypothèses de la méthode. Le calcul décimal utilise 50 chiffres significatifs, mais les estimations, méthodes numériques et données sources peuvent être moins précises ; l’arrondi affiché ne supprime pas ces limites. Exemples résolus vérifiés à partir de sources indépendantes : 9. Par exemple, « Yellow violet red gold » est vérifié à l’aide de IEC 60062 table: 4,7 × 10² Ω, gold = ±5%; 4700 × 0.95 / 1.05.

Q: D’où vient cette méthode ?

IEC 60062:2016 — Marking codes for resistors and capacitors (colour code, tolerance and TCR bands); IEC 60063:2015 — Preferred number series for resistors and capacitors (E series); Wikipedia — Electronic color code (summary of the IEC 60062 table).

Resistor colour code calculator for 4, 5 and 6-band resistors: colours to ohms and tolerance, or a value to its bands, snapped to E12, E24 or E96.

Mis à jour 28 septembre 2026Exemples vérifiés : 9

Resistance

Chiffres significatifs : 6 ; Au plus proche, égalités en s’éloignant de zéro

Marked value: 4.7 kΩ ±5%
Bands: yellow, violet, red, gold
Tolerance: 5%
Minimum within tolerance: 4,465Ω
Maximum within tolerance: 4,935Ω
Smallest E-series containing the value: E6

Bands yellow, violet, red, gold mark 4.7 kΩ ±5%: any part between 4.465 kΩ and 4.935 kΩ is in spec. The value is in the E6 series.

4.7 kΩ ±5%

Comment le calcul est effectué S

Digits and multiplier
$R = 47 \times 10^{2} = 4{,}700\ \mathrm{\Omega}$
Bands: yellow, violet → 47; red → ×10^2.
Tolerance range
$R(1 \mp 0.05) = 4{,}465\ \text{to}\ 4{,}935\ \mathrm{\Omega}$

À propos de Resistor colour code calculator

The resistor colour code in IEC 60062 marks a value with coloured bands: two or three significant digits, a multiplier band that gives the power of ten, a tolerance band, and on 6-band parts a temperature-coefficient band. It works both ways here: pick the colours to get the resistance and its tolerance range, or type a resistance to get the bands.

The default, yellow violet red gold, reads 47 × 10² Ω = 4.7 kΩ ±5%, so a part measuring anywhere from 4,465 Ω to 4,935 Ω is in specification. Going from a value to colours, the value can first be snapped to the nearest IEC 60063 preferred value: 5 kΩ is not in E12, so it becomes 4.7 kΩ, yellow violet red.

Gold and silver never start a reading because they carry no digit. When bands are faded or look alike, confirm the value with a multimeter.

Exemples détaillés

Yellow violet red gold

Direction: Colours → value
Number of bands: 4 bands
Band 1 (first digit): Yellow
Band 2 (second digit): Violet
Multiplier band: Red
Tolerance band: Gold

Resistance: 4,700 Ω
Tolerance: 5%
Minimum within tolerance: 4,465 Ω
Maximum within tolerance: 4,935 Ω
Marked value: 4.7 kΩ ±5%

Source de vérification : IEC 60062 table: 4,7 × 10² Ω, gold = ±5%; 4700 × 0.95 / 1.05

Brown black black brown brown (5 band)

Direction: Colours → value
Number of bands: 5 bands
Band 1 (first digit): Brown
Band 2 (second digit): Black
Band 3 (third digit): Black
Multiplier band: Brown
Tolerance band: Brown

Resistance: 1,000 Ω
Tolerance: 1%
Minimum within tolerance: 990 Ω

Source de vérification : IEC 60062 table: 100 × 10¹ Ω ±1%

5 kΩ snapped to E12

Direction: Value → colours
Number of bands: 4 bands
Resistance: 5000
Resistance unit: Ω
Snap to series: E12
Tolerance: Silver

Resistance: 4,700 Ω
Bands: yellow, violet, red, silver

Source de vérification : IEC 60063 E12 neighbours 4.7k and 5.6k: 5000/4700 = 1.064 < 5600/5000 = 1.12

6 band with 50 ppm/K

Direction: Colours → value
Number of bands: 6 bands
Band 1 (first digit): Orange
Band 2 (second digit): Orange
Band 3 (third digit): Black
Multiplier band: Brown
Tolerance band: Brown
Temperature coefficient band: Red

Resistance: 3,300 Ω
Temperature coefficient: 50 ppm/K
Smallest E-series containing the value: E6

Source de vérification : IEC 60062 table: 330 × 10 Ω, brown ±1%, red TCR 50 ppm/K

Questions

How do you read a 4-band resistor colour code?

The first two bands are digits, the third is the multiplier and the fourth the tolerance. The digits run black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Yellow, violet, red, gold therefore reads 47 × 10² = 4,700 Ω, with gold meaning ±5%.

Which end of a resistor do you start reading from?

Start from the end away from the gold or silver band. Gold and silver have no digit value in IEC 60062; they only appear as a multiplier (×0.1 and ×0.01) or a tolerance (±5% and ±10%). The first band usually sits closer to its lead, and the tolerance band is often spaced apart from the others.

What is the difference between 4, 5 and 6-band resistors?

A 4-band resistor carries two significant digits, enough for the E6 to E24 values used for ±5% to ±20% parts. A 5-band resistor carries three digits for the E48 to E192 values of ±2% and tighter parts: brown, black, black, red, brown is 100 × 10² Ω = 10 kΩ ±1%. A 6-band resistor adds a temperature-coefficient band.

What does the temperature coefficient band mean?

It gives the resistance drift per kelvin in parts per million: brown 100 ppm/K, red 50, yellow 25, green 20, orange 15, blue 10, violet 5 and grey 1. A 3.3 kΩ resistor with a red band changes by 3,300 × 50 × 10⁻⁶ = 0.165 Ω per degree, about 4.1 Ω over a 25 °C rise.

What if a resistor has only three bands?

A missing tolerance band means ±20%. Brown, black, orange with no fourth band is 10 kΩ, and any value from 8 kΩ to 12 kΩ is within specification. Such parts come from the E6 series (1.0, 1.5, 2.2, 3.3, 4.7, 6.8), whose steps of about 47% suit the wide tolerance.

Quelle est la précision de « Resistor colour code calculator » ?

La précision dépend de vos données et des hypothèses de la méthode. Le calcul décimal utilise 50 chiffres significatifs, mais les estimations, méthodes numériques et données sources peuvent être moins précises ; l’arrondi affiché ne supprime pas ces limites. Exemples résolus vérifiés à partir de sources indépendantes : 9. Par exemple, « Yellow violet red gold » est vérifié à l’aide de IEC 60062 table: 4,7 × 10² Ω, gold = ±5%; 4700 × 0.95 / 1.05.

D’où vient cette méthode ?

IEC 60062:2016 — Marking codes for resistors and capacitors (colour code, tolerance and TCR bands); IEC 60063:2015 — Preferred number series for resistors and capacitors (E series); Wikipedia — Electronic color code (summary of the IEC 60062 table).

À propos de ce calculateur

R = (d_1d_2[d_3]) \times 10^{m},\qquad R_{\min,\max} = R\,(1 \mp t)

Sources

IEC 60062:2016 — Marking codes for resistors and capacitors (colour code, tolerance and TCR bands)
IEC 60063:2015 — Preferred number series for resistors and capacitors (E series)
Wikipedia — Electronic color code (summary of the IEC 60062 table)

Vérifié avec les références

Ce calculateur comprend 9 exemples résolus dont les réponses proviennent de sources indépendantes. Ils font partie de la suite de tests et peuvent aussi être exécutés ici.