# 6 Band Resistor Calculator

Calculate the resistance of a 6 band resistor

## Resistance Calculator

## 6 Band Resistor

### Outputs

Resistance:

Tolerance:

Tempco:

#### Introduction

A resistor is a perhaps the most common building block used in circuits. Resistors come in many shapes and sizes this tool is used to decode information for color banded axial lead resistors.

#### 6 Band Description

The number of bands is important because the decoding changes based upon the number of color bands. There are three common types: 4 band, 5 band, and 6 band resistors. For the 6 band resistor:

**Band 1** – first significant digit.

**Band 2** – second significant digit

**Band 3** – third significant digit

**Band 4** – Multiplier

**Band 5** – Tolerance

**Band 6** – Temperature Coefficient (Tempco)

#### Resistance Value

The first 4 bands make up the resistance nominal value. The first 3 bands make up the significant digits where:

**black – 0**

**brown – 1**

**red – 2**

**orange – 3**

**yellow – 4**

**green – 5**

**blue – 6**

**violet – 7**

**grey – 8**

**white – 9**

The multiplier band is color coded as follows:

**black – x1**

**brown – x10**

**red – x100**

**orange – x1K**

**yellow – x10K**

**green – x100K**

**blue – x1M**

**violet – x10M**

**grey – x100M**

**white – x1G**

**gold – .1**

**silver – .01**

An example of a resistance value is:

band 1 = orange = 3,

band 2 = yellow = 4,

band 3 = green = 5,

band 4 = blue = 1M

value = 345*1M = 345 Mohm

#### Resistance Tolerance

The fifth band is the tolerance and represents the worst case variation one might expect from the nominal value. The color code for tolerance is as follows:

**brown – 1%**

**red – 2%**

**orange – 3%**

**yellow – 4%**

**green – .5%**

**blue – .25%**

**violet – .1%**

**gray – .05%**

**gold – 5%**

**silver – 10%**

An example calculating the range of a resistor value is:

If the nominal value was 345 Ohm and the 5th band of the resistor was gold (5%) the value range would be nominal +/- 5% = 327.75 to 362.25

#### Resistance Temperature Coefficient

Resistors values can change with temperature. The 6th band represents the temperature coefficient or tempco and is represents the amount the resistance value will change with temperature. It is in units of ppm/degree C. The band colors represents the following:

**brown – 100 ppm/ºC**

**red – 50 ppm/ºC**

**orange – 15 ppm/ºC**

**yellow – 25 ppm/ºC**

**blue – 10 ppm/ºC**

**violet – 5 ppm/ºC**

An example if a resistor had a nominal value of 1K ohm and a tempco of 100 ppm/ºC and we wanted to know how much a resistor would change of 25ºC.

100*25/1e6*1K= 2.5 ohm variation over 25ºC.