# 4 Band Resistor Calculator

Calculate the resistance of a 4 band resistor

## Resistance Calculator

## 4 Band Resistor

### Outputs

Resistance:

Tolerance:

#### 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.

#### 4 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 4 band resistor:

**Band 1** – First significant digit.

**Band 2** – Second significant digit

**Band 3** – Multiplier

**Band 4** – Tolerance

#### Resistance Value

The first 4 bands make up the resistance nominal value. The first 2 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 3rd band or 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 = blue = 1M

value = 34*1M = 34 Mohm

#### Resistance Tolerance

The fourth 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 34 Ohm and the 4th band of the resistor was gold (5%) the value range would be nominal +/- 5% = 32.3 to 35.7