~ Preferred Component Value Calculator ~

 

Required Value		Error	Tolerance ±
EIA Series E6			20 %
EIA Series E12			10 %
EIA Series E24			5 %  2 %  1 %
EIA Series E48			2 %  1 %
EIA Series E96			1 %
EIA Series E192			0.5 %  0.25 %  0.1 %

 

The Electronic Industries Association (EIA) specifies standard values for components which I have always known as the 'preferred values' that I learned from my dad an early age along with the colour code for reading them ~ which is much easier when you are taught the values are limited and repeat in decades

The series numbers E6 to E192 indicate the number of Exponential or logarithmic values in each decade ~ The E12 series found in most vintage equipment has values 10,12,15,18,22,27,33,39,47,56,68,82 then 100,120,150 . . . with a tolerance ±10% so any value +10% matches the next value up ‑10%

The value in the tolerance column dictates the series based on selecting resistors to fit 'tolerance bins' so that none are wasted in manufacture ~ Nowadays manufacturing is more accurate and many makers supply higher tolerances than the series values would indicate

If you want to make an odd value from a series or parallel combination of 2 resistors then check this calculator  or click here for other calculators

 

" Rikki don't lose that number ~ You don't wanna call nobody else "