Resistor Calculator
Color Code ยท Parallel ยท Series ยท Conductor Resistance
Find the resistance (Ohms) and tolerance from resistor color bands. Supports 3, 4, 5, and 6 band resistors per IEC 60062 standard.
๐ Color Code Reference Table
| Color | Sig. Figure | Multiplier | Tolerance | Temp. Coeff. |
|---|---|---|---|---|
| Black | 0 | ร 1 | โ | 250 ppm/K (U) |
| Brown | 1 | ร 10 | ยฑ1% (F) | 100 ppm/K (S) |
| Red | 2 | ร 100 | ยฑ2% (G) | 50 ppm/K (R) |
| Orange | 3 | ร 1K | ยฑ0.05% (W) | 15 ppm/K (P) |
| Yellow | 4 | ร 10K | ยฑ0.02% (P) | 25 ppm/K (Q) |
| Green | 5 | ร 100K | ยฑ0.5% (D) | 20 ppm/K (Z) |
| Blue | 6 | ร 1M | ยฑ0.25% (C) | 10 ppm/K (Z) |
| Violet | 7 | ร 10M | ยฑ0.1% (B) | 5 ppm/K (M) |
| Grey | 8 | ร 100M | ยฑ0.01% (L) | 1 ppm/K (K) |
| White | 9 | ร 1G | โ | โ |
| Gold | โ | ร 0.1 | ยฑ5% (J) | โ |
| Silver | โ | ร 0.01 | ยฑ10% (K) | โ |
| None | โ | โ | ยฑ20% (M) | โ |
Enter resistance values separated by commas. Formula: 1/Rtotal = 1/R1 + 1/R2 + ... + 1/Rn
Enter resistance values separated by commas. Formula: Rtotal = R1 + R2 + ... + Rn
Calculate the resistance of a round wire/conductor. Formula: R = L / (A ร C) โ where L = length, A = cross-sectional area, C = conductivity.
โก What is a Resistor?
A resistor is a passive electronic component that limits current flow in a circuit. Resistance is measured in Ohms (ฮฉ), named after Georg Simon Ohm. They protect components, divide voltages, and set operating points in circuits.
๐ข Ohm's Law
The relationship between Voltage, Current, and Resistance is: V = I ร R. If you know any two values, you can calculate the third. This is the fundamental law of all electrical circuits.
โซฆ Parallel vs Series
In series, resistances add up โ total is always larger than any single resistor. In parallel, total resistance is always smaller than the smallest resistor, because current has multiple paths to flow through.
๐ Color Code Standard
The resistor color code (IEC 60062, standardized 1952) uses colored bands because components are too small for printed text. Each color represents a digit (0โ9), a multiplier, tolerance, or temperature coefficient.