Resistance and Tolerance Calculator

Calculator:











What is a Resistor?

A resistor is identified by its pattern of color of bands. There are 4, 5 and 6
band resistors. To calculate resistance, you can select the appropriate option of colours in the above Resistance and Tolarence Calculator.
Resistor Example

How to Calculate Resistance Manually?

You can calculate resistance manually by referring to the table below. You can use the following formula.

Resistance= ab.c+-d%

Colour Code Chart

Which Band is First?

The short answer: You'll know that from experience! But there are some rules you can follow:

1.) Some resistors have the color bands grouped together and/or close to one end. Hold the resistor with the closely grouped bands to your left and read the resistor from the left to the right.
2.) With 5% and 10% resistors the procedure is simple: hold the resistor with the silver or gold band to the right and read the resistor from the left to the right.
3.) The first band can't be silver or gold, so if you hold such a resistor you'll know instantly where to start. Also, the 3rd color for 4-band resistors will be blue (106) or less and the 4th color for 5 band resistors will be green (105) or less, as basic resistor values range from 0.1 Ohm to 10 Ohms.
Right Way to Read a Resistor