Resistor calculator
Resistor calculator
A resistor is an electronic component that limits the flow of current in a circuit. Here’s a simple calculator to help you calculate the resistance of a resistor:
- Determine the color bands on your resistor. Typically, resistors have four or five color bands that indicate the value of the resistance.
- Find the tolerance of the resistor. The tolerance is indicated by a colored band that is separate from the other bands. The tolerance band indicates the range of values that the actual resistance of the resistor may fall within.
- Use the color codes to determine the resistance value of the resistor. Each color band corresponds to a digit. The first two bands represent the first two digits of the resistance value, the third band represents a multiplier that determines the number of zeros to add to the first two digits, and the fourth band (if present) indicates the tolerance.
Here’s a table of the color codes:
| Color Code | 1st Band | 2nd Band | Multiplier | Tolerance |
|---|---|---|---|---|
| Black | 0 | 0 | 1 | |
| Brown | 1 | 1 | 10 | ±1% |
| Red | 2 | 2 | 100 | ±2% |
| Orange | 3 | 3 | 1,000 | |
| Yellow | 4 | 4 | 10,000 | |
| Green | 5 | 5 | 100,000 | ±0.5% |
| Blue | 6 | 6 | 1,000,000 | ±0.25% |
| Violet | 7 | 7 | 10,000,000 | ±0.1% |
| Gray | 8 | 8 | 100,000,000 | ±0.05% |
| White | 9 | 9 | 1,000,000,000 | |
| Gold | 0.1 | ±5% | ||
| Silver | 0.01 | ±10% |
- Calculate the resistance value. Once you know the digit values of the color bands, you can use the following formula to calculate the resistance value:
Resistance = (1st digit × 10 + 2nd digit) × multiplier
For example, if a resistor has the color bands brown-black-red-gold, the resistance value would be:
Resistance = (1 × 10 + 1) × 100 = 110 Ω with a tolerance of ±1%.
I hope that helps you! Let me know if you have any further questions.