Resistor Color Code Calculator
Decode resistor color bands or SMD codes into resistance values, and back.
Result
1 kΩ ±5%
Tolerance range: 950 Ω – 1.05 kΩ
Usage examples
Checking a resistor's value on a circuit board
Pick the exact color bands printed on a resistor to instantly see its resistance and tolerance range.
Decoding an SMD resistor's printed code
Enter a code like '103' or '4R7' printed on a surface-mount resistor to find its actual resistance value.
Finding the color band combination for a target value
Work backward from a needed resistance to the color bands, so you can pick the right resistor from a parts bin.
Frequently asked questions
Is what I enter sent to a server?
No. All calculations happen entirely in your browser and are never sent to a server.
Which end do I start reading the bands from?
The tolerance band (often gold or silver) is usually spaced further apart from the others — that's the last band. Read from the opposite end, left to right, with the tolerance band on the right.
Is the 6th band (temperature coefficient) always present?
No. The temperature coefficient band only appears on precision resistors as a 6th band — ordinary 4- and 5-band resistors don't have it.
What do R, K, and M mean in an SMD code?
They mark both the decimal point position and the unit. R means ×1 (Ω), K means ×1,000 (kΩ), and M means ×1,000,000 (MΩ) — the letter sits where the decimal point goes. For example, 4R7 = 4.7Ω and 4K7 = 4.7kΩ.