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: “Resistor colour code calculator” chính xác đến mức nào?

Độ chính xác phụ thuộc vào dữ liệu nhập và giả định của phương pháp. Phép tính thập phân dùng 50 chữ số có nghĩa, nhưng ước lượng, phương pháp số và dữ liệu nguồn có thể kém chính xác hơn; làm tròn khi hiển thị không loại bỏ các giới hạn đó. Ví dụ có lời giải đã đối chiếu với nguồn độc lập: 9. Ví dụ, “Yellow violet red gold” được kiểm tra bằng IEC 60062 table: 4,7 × 10² Ω, gold = ±5%; 4700 × 0.95 / 1.05.

Q: Phương pháp này lấy từ đâu?

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.

Cập nhật 28 tháng 9, 2026Ví dụ đã kiểm tra: 9

Resistance

Số chữ số có nghĩa: 6; Gần nhất; nếu cách đều thì ra xa số không

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%

Cách tính S

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

Giới thiệu 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.

Ví dụ có lời giải

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%

Nguồn đối chiếu: 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

Nguồn đối chiếu: 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

Nguồn đối chiếu: 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

Nguồn đối chiếu: IEC 60062 table: 330 × 10 Ω, brown ±1%, red TCR 50 ppm/K

Câu hỏi

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.

“Resistor colour code calculator” chính xác đến mức nào?

Độ chính xác phụ thuộc vào dữ liệu nhập và giả định của phương pháp. Phép tính thập phân dùng 50 chữ số có nghĩa, nhưng ước lượng, phương pháp số và dữ liệu nguồn có thể kém chính xác hơn; làm tròn khi hiển thị không loại bỏ các giới hạn đó. Ví dụ có lời giải đã đối chiếu với nguồn độc lập: 9. Ví dụ, “Yellow violet red gold” được kiểm tra bằng IEC 60062 table: 4,7 × 10² Ω, gold = ±5%; 4700 × 0.95 / 1.05.

Phương pháp này lấy từ đâu?

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).

Về công cụ tính này

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

Nguồn

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)

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