How to identify inductor markings

Inductors can be labeled with a number of different ways. The most common are text codes and color codes.



Text Marking



 * xRx values are in micro Henries (μH)
 * Three digit values are in nano Henries (nH) or micro Henries (μH), depending on manufacturers choice
 * First two digits are the value
 * Third digit is the multiplier (or number of zeros added to the value)
 * If there is an R, its acts as a decimal point, and there is no multiplier
 * Examples:
 * 472 = 47*102nH = 4700nH = 4.7μH (Coilcraft)
 * 472 = 47*102μH = 4700μH = 4.7mH (Bourns)
 * 4R7 = 4.7μH


 * Suffix
 * Sometimes the precision of the inductor will be marked, using a final letter F, G, J, K, or M
 * F = +/-1%
 * G = +/-2%
 * J = +/-5%
 * K = +/-10%
 * M = +/-20%

Color Code Markings
Inductors can be marked by colored bands or colored dots. Each color represents a value.

''note: brown and violet can look very similar on some components. Violet and white can also look similar sometimes''

Example 47 micro Henry




 * Band colors:
 * 1st band: yellow=4
 * 2nd band: violet=7
 * 3rd band: black=10^0=1
 * Inductor value = 47x10^0uH = 47uH
 * 4th band: silver = 10% tolerance
 * inductance=47+-10