In practice some deviations may occur, e.g. That’s the basic idea behind standard resistor series.
#Standard 1% resistor values series
The typical tolerances for the E12 series resistor values are 10%, for the E24 series it’s 5% and for the E96 series tolerances are down to 1%. The higher the number of the E-series the more divisions per decade exist and thus the precision of the resistors values increases. It works analogous for the other E-series. This is done in a way that each part is equally spaced on a logarithmic scale, i.e. Knowing the common resistor values can help a lot when trying to decode the colored stripes on a resistor ?Īs an example, for the E12 set of resistor values every decade of resistance values is divided into 12 equal parts. The E12-series is obtained by skipping even row numbers. The following graphic shows the values and color codings for the E24 series. This way manufacturers only need to produce and store a limited variety of different resistors and consumers can rely on the fact that resistors of different manufacturers are interchangeable. The specific resistor values are standardized in the EIA “E range” of standards, with EIA E12 and EIA E24 being the most common. In reality only a selected range of resistor values is available. However, in reality there is no 23.94 Ohms resistor available as standard off-the-shelf (SOTS) electronic part. When we learn the theory behind electronic circuits we often calculate the exact value a certain resistor, capacitor or inductance should have.