Resistor Color Code Calculator (4 and 5 Bands)
Resistance and tolerance range of a resistor from the colours of its bands, for 4-band and 5-band resistors.
Results
Resistance
1000
Ω
Lowest value within tolerance
950
Ω
Highest value within tolerance
1050
Ω
What this tool does
Read the bands starting from the end where they are bunched together; the tolerance band, usually gold or silver on 4-band resistors, sits apart on the other end. The first two bands (three on precision 5-band resistors) are digits and the next one is the power of ten — so brown, black, red means 1, 0 and two zeros: 1000 Ω. If the colours are hard to tell apart, a multimeter settles it; the measured value should fall within the range shown.
Formula
R = (digits) × multiplier · 4 bands: d1 d2 × m · 5 bands: d1 d2 d3 × m
Variables
| Symbol | Meaning | Unit |
|---|---|---|
b1 | 1st band (first digit) | — |
b2 | 2nd band (second digit) | — |
b3 | 3rd digit band (5-band resistors only) | — |
mu | Multiplier band | — |
to | Tolerance band | — |
R | Resistance | Ω |
RN | Lowest value within tolerance | Ω |
RX | Highest value within tolerance | Ω |
Worked example
- 1st band (first digit)1
- 2nd band (second digit)0
- 3rd digit band (5-band resistors only)-1
- Multiplier band100
- Tolerance band5
- Resistance1000 Ω
- Lowest value within tolerance950 Ω
- Highest value within tolerance1050 Ω
Limitations
- Coverage and consumption figures vary between products. Take the values from the manufacturer's datasheet for the product you are actually using.
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.