How to use the resistor color code calculator
- Colour bands → value: count the bands on your resistor (4, 5 or 6), pick that many, then tap the colour of each band from left to right. The value, tolerance and the range a good part measures in appear at once.
- Value → colour bands: type a value the way you'd write it (
4.7k,4k7,470R,2.2M,R47), choose the number of bands and the tolerance, and you get the colours to look for. If the value isn't one you can buy, the calculator names the nearest standard value with one tap to use it. - SMD code: type the code printed on a chip resistor (
472,1002,4R7,01C) to get its value.
Share result gives you a link that opens the same bands or code for someone else, for example in a parts list or a forum question.
The colour code
Each colour stands for a digit, a multiplier, a tolerance or a temperature coefficient, depending on the band's position. The colours follow IEC 60062, the international standard for marking resistors and capacitors:
| Colour | Digit | Multiplier | Tolerance | TCR (6th band) |
|---|---|---|---|---|
| Black | 0 | ×1 | ||
| Brown | 1 | ×10 | ±1 % | ±100 ppm/K |
| Red | 2 | ×100 | ±2 % | ±50 ppm/K |
| Orange | 3 | ×1 k | ±15 ppm/K | |
| Yellow | 4 | ×10 k | ±25 ppm/K | |
| Green | 5 | ×100 k | ±0.5 % | |
| Blue | 6 | ×1 M | ±0.25 % | ±10 ppm/K |
| Violet | 7 | ×10 M | ±0.1 % | ±5 ppm/K |
| Grey | 8 | ×100 M | ±0.05 % | |
| White | 9 | ×1 G | ||
| Gold | ×0.1 | ±5 % | ||
| Silver | ×0.01 | ±10 % | ||
| Pink | ×0.001 | |||
| No band | ±20 % |
A 4-band resistor has two digits, a multiplier and a tolerance: yellow, violet, red, gold is 47 × 100 = 4.7 kΩ ±5 %. A 5-band resistor has three digits, so it can mark values like 4.75 kΩ (yellow, violet, green, brown, brown). A 6-band resistor adds the temperature coefficient: how many millionths of its value it drifts per degree.
Which way round?
The tolerance band is set apart from the others or drawn wider, so start reading from the other end. If the bands look evenly spaced, try both directions with Flip: gold and silver can't be digits, so a code that starts with them is backwards. Faded paint makes red, orange and brown hard to tell apart, and the body colour can hide a band, so check a doubtful part with a multimeter, out of the circuit.
Standard values (E series)
Resistors are made in preferred values. The E6 series (10, 15, 22, 33, 47, 68) is for ±20 % parts, E12 has 12 values per decade (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82) for ±10 % parts, E24 has 24 for ±2 % and ±5 %, E96 has 96 for ±1 % and E192 covers ±0.5 % and tighter. When a calculation gives you 5 kΩ, the nearest E24 part is 5.1 kΩ; in E96 it is 4.99 kΩ. The value tab shows both neighbours so you can round in the safe direction for your circuit.
SMD resistor codes
Chip resistors print the value instead of bands, and no tolerance:
- 3 digits: two digits and the number of zeros.
472= 4,700 Ω,330= 33 Ω (not 330). - 4 digits: three digits and the number of zeros, for 1 % parts.
1331= 1,330 Ω. - R as the decimal point:
4R7= 4.7 Ω,R10= 0.1 Ω. Some makers use L for milliohms:10L0= 0.01 Ω. - EIA-96, used on small 1 % chips such as the 0603 size: two digits pick a value from the E96 list (01 = 100, 02 = 102 … 96 = 976) and a letter multiplies it: Y or S ×0.01, X or R ×0.1, A ×1, B or H ×10, C ×100, D ×1,000, E ×10,000.
01C= 10 kΩ and07B= 1.15 kΩ.
A code like 47R can be read two ways (47 Ω in R notation, or 30.1 Ω in EIA-96), so the calculator shows both.
Sources
Colours, multipliers, tolerances and the temperature coefficient band: Vishay's resistor marking guide (colour code according to IEC 60062) and TT Electronics' TN004, which also gives the EIA-96 table. Pink (×0.001) comes from the 2016 edition of IEC 60062. E-series values: Vishay's standard decade value tables.
Related tools
Building something with a microcontroller? Watch what your board prints with the serial monitor, make a test signal with the tone generator, check a DIY controller in the MIDI tester, or sketch a layout on graph paper.