Parts Per Million (PPM) Calculator

Resistor Tolerance- parts per million (ppm)


This Parts Per Million (PPM) Calculator calculates the tolerance of an electronic component, such as a resistor or capacitor.

A user just has to enter the nominal value of an electronic component and its specified parts per million tolerance value, and click the 'Calculate' button, and the result will automically be calculated and shown. The resultant value represents the tolerance value of the electronic component.

The nominal value of a component is its stated value. For example, the nominal value of a 10KΩ resistor is 10KΩ. If you actually took an ohmmeter and measured its resistance, it may not be 10KΩ because resistors have tolerance values, meaning they aren't precise but can vary. However, its stated or nominal value is key to calculating how much it can vary off its nominal value.

The parts per million value represents the component's tolerance. It represents how much the electronic component may vary from its nominal value.

Sometimes, the tolerance of an electronic component is specified according to a percent value. For example, a 10KΩ may have a 10% tolerance rating. This means its resistance can be 10% higher or lower than its stated nominal value, which is 10KΩ. This means that its resistance may be as low as 9KΩ or as high as 11KΩ or somewhere in between. However, tolerance of components may also be specified according to parts per million. For example, if a resistor has a tolerance rating of 500ppm, this means that for every million ohms of resistance, it may vary 500Ω off from this amount. So a 1MΩ resistor may vary as much as 500Ω greater or less than its nominal value. As another example, a 10KΩ resistor with 500 ppm can vary as much as 5Ω off its nominal value, since 10KΩ/1,000,000= 0.01*500= 5Ω.

And this parts per million calculation is used for other electronic components such as capacitors as well to determine tolerance values.

Example Calculations

Find the tolerance value of a 1KΩ resistor which has a parts per million specification of 5000 ppm.


1KΩ/1000000= 0.001

0.001 * 5000= 5

So the tolerance of the resistor is 5Ω.

Find the tolerance value of a 1F capacitor which has a parts per million specification of 20000 ppm.


1/1000000= 0.000001

0.000001 * 20000= 0.02

So the tolerance of the capacitor is 20mF.

Related Resources

Parts per Million (PPM)- Explained

Resistor Tolerance