Inductor Color Code Calculator

Inductors — the coil-shaped components found on circuit boards — are marked with colored bands that encode their value, much like resistor color codes. Select 4 or 5 bands, then choose your 1st Band, 2nd Band, 3rd Band, Multiplier Band, and Tolerance Band colors in the Inductor Color Code Calculator to get the Inductance Value in µH. Secondary outputs include Tolerance, and the Minimum and Maximum values based on that tolerance.

Number of Bands *

Results

Inductance Value

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Tolerance

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Minimum Value

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Maximum Value

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Frequently Asked Questions

How do I read a 4-band inductor color code?

For 4-band inductors, the first two bands represent digits, the third band is the multiplier, and the fourth band is tolerance. Read from left to right and multiply the two-digit number by the multiplier value.

What's the difference between 4-band and 5-band inductors?

5-band inductors have an additional third digit for higher precision, while 4-band inductors use only two significant digits. 5-band inductors also sometimes include a military identifier band.

What does the tolerance band indicate?

The tolerance band shows the acceptable variation from the nominal inductance value as a percentage. For example, ±5% means the actual value can be 5% higher or lower than the calculated value.

Why do some inductors use numbers instead of color bands?

Smaller inductors often use printed numbers because color bands would be too small to read accurately. Surface-mount inductors typically use numerical coding systems instead of color bands.

What units are inductance values measured in?

Inductance is measured in henries (H), with common sub-units being millihenries (mH), microhenries (µH), and nanohenries (nH). Most small inductors are measured in microhenries.

How accurate are color-coded inductors?

Color-coded inductors typically have tolerances ranging from ±1% to ±20%, with ±5% and ±10% being most common. Higher precision inductors usually have tighter tolerances but cost more.

Can I use this calculator for both air core and ferrite core inductors?

Yes, this calculator works for any color-coded inductor regardless of core material. The color code standard applies to air core, ferrite core, and other types of inductors.

What should I do if a color band is hard to distinguish?

Use good lighting and compare with a color chart. If still unclear, measure the inductance with an LCR meter for accuracy. Some colors like orange/red or brown/violet can be difficult to distinguish.