# Resistor Color Code Calculator

URL: https://speedycalculator.com/calculators/physics/resistor-color-code/
Last updated: 2026-10-30

> The resistor color code calculator decodes 4-, 5- and 6-band resistor colour codes into resistance, tolerance range and temperature coefficient.

## Inputs

- Number of bands
- Band 1 (1st digit)
- Band 2 (2nd digit)
- Band 3 (3rd digit)
- Multiplier band
- Tolerance band
- Temperature coefficient band

## Results

- Resistance
- Minimum
- Maximum
- Temperature coefficient

## Formula

```
4 bands: R = (10·d₁ + d₂) × multiplier · 5–6 bands: R = (100·d₁ + 10·d₂ + d₃) × multiplier
```

## Explanation

Through-hole resistors are marked with coloured bands instead of printed numbers. The first two or three bands are digits, the next is a power-of-ten multiplier, then the tolerance – and on 6-band resistors a temperature coefficient.

### How to use the Resistor Color Code Calculator

- **Number of bands**
- **Band 1 (1st digit)**
- **Band 2 (2nd digit)**
- **Band 3 (3rd digit)**
- **Multiplier band**
- **Tolerance band**
- **Temperature coefficient band**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Choose the number of bands and pick the colour of each band from left to right.

### Inputs explained

FieldWhat to enterNumber of bandsChoose one: 4 bands, 5 bands, 6 bandsBand 1 (1st digit)Choose one: Brown (1), Red (2), Orange (3), Yellow (4) …Band 2 (2nd digit)Choose one: Black (0), Brown (1), Red (2), Orange (3) …Band 3 (3rd digit)Choose one: Black (0), Brown (1), Red (2), Orange (3) …Multiplier bandChoose one: Black (×1), Brown (×10), Red (×100), Orange (×1k) …Tolerance bandChoose one: Brown (±1%), Red (±2%), Green (±0.5%), Blue (±0.25%) …Temperature coefficient bandChoose one: Black (250 ppm/K), Brown (100 ppm/K), Red (50 ppm/K), Orange (15 ppm/K) …

### What each result means

- **Minimum** = [Resistance]×(1 - [Tolerance band]÷100)
- **Maximum** = [Resistance]×(1 + [Tolerance band]÷100)

## Worked example

Inputs — Number of bands: 4 bands; Band 1 (1st digit): Brown (1); Band 2 (2nd digit): Black (0); Multiplier band: Red (×100); Tolerance band: Gold (±5%).

Results — **Resistance = 1,000 Ω**; Minimum = 950 Ω; Maximum = 1,050 Ω.

## Key terms

- **Tolerance**: Allowed deviation from the nominal value.

## FAQ

**How do I know which end to start from?**
The tolerance band (often gold or silver) is usually set apart on the right.

**What does brown-black-red-gold mean?**
1, 0, ×100, ±5% = 1 kΩ ± 5%.

**Why do 5-band resistors exist?**
Precision resistors need three significant digits.

**Is there a mnemonic?**
"Bad Beer Rots Our Young Guts But Vodka Goes Well" – black to white.


## Sources

- [OpenStax – University Physics Volume 2](https://openstax.org/details/books/university-physics-volume-2)
- [The Engineering ToolBox](https://www.engineeringtoolbox.com/)
- [IEC 60062 – Marking codes for resistors and capacitors](https://webstore.iec.ch/publication/24356)