Resistor Color Code Calculator (4, 5 and 6 Band)
Choose bands to read the colours on a resistor, or choose value to bands to find the colours for a standard value. Fields that do not apply to the chosen mode or band count are ignored.
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Formula
- 4 band:
value = (10 × digit1 + digit2) × multiplier, tolerance from band 4. - 5 band:
value = (100 × digit1 + 10 × digit2 + digit3) × multiplier, tolerance from band 5. - 6 band: as 5 band, with band 6 giving the temperature coefficient in ppm/K.
- Range:
value × (1 ± tolerance ÷ 100).
Digits: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Multipliers: ×10 to the power of the digit, gold ×0.1, silver ×0.01. Tolerance: brown 1%, red 2%, green 0.5%, blue 0.25%, violet 0.1%, orange 0.05%, yellow 0.02%, grey 0.01%, gold 5%, silver 10%, no band 20% (4 band only).
Value to bands snaps to the nearest standard value of the series (E12 ±10%, E24 ±5%, E96 ±1%, IEC 60063) on a logarithmic scale, then writes its digits and multiplier as colours.
Worked example
Yellow, violet, red, gold: digits 4 and 7 give 47, red multiplier ×100, so 4700 Ω at ±5%. The range is 4700 × 0.95 = 4465 Ω to 4700 × 1.05 = 4935 Ω.
Reverse: 4800 Ω in E12 snaps to 4700 Ω, which is yellow, violet, red, silver.
Frequently asked questions
How do I read a 4 band resistor?
The first two bands are digits, the third is the multiplier and the fourth is the tolerance. Yellow, violet, red, gold is 47 × 100 = 4700 Ω (4.7 kΩ) at ±5%.
What is the difference between 4, 5 and 6 band resistors?
A 5 band resistor adds a third digit for precision parts: brown, black, black, brown, brown is 100 × 10 = 1000 Ω at ±1%. A 6 band resistor adds a temperature coefficient band, for example brown for 100 ppm/K.
Which end do I start reading from?
Start from the end where the bands sit closest together and away from the gap. The tolerance band, often gold or silver, is usually the last one.
How do I find the colours for a standard value?
Choose value to bands, pick E12, E24 or E96 and type the resistance. The calculator snaps to the nearest standard value, so 4800 Ω in E12 becomes 4700 Ω, and shows its colours.
Can this be used to check a real circuit?
It is for learning and design checks, not safety certification. Colours can be hard to tell apart (red, brown and orange), so confirm the value with a multimeter before relying on a part.
What range of values can be converted to bands?
Up to 50 GΩ. Down to 0.1 Ω for 4 bands, but 5 and 6 band codes only start at 1 Ω because the 3-digit codes below that would need a ×0.001 multiplier, which does not exist; such values are rejected. In reverse mode the temperature coefficient band is the one you choose (brown, 100 ppm/K, by default) and only appears for 6 bands.