Resistor Calculator
Decode resistor colour bands (4, 5 or 6 band) and compute series/parallel networks.
Inputs
Resistance
1,000.0000Ω
Tolerance
±5%
Value Range
1.000 kΩ – 1.000 kΩ
Temperature Coefficient
n/a
Band Sequence
brown black | red | gold
Step by step
Digit bands
= brown(1) black(0) = 10
Multiplier
= red → × 100
Resistance
= 1.000 kΩ
Tolerance
= ±5% → 1.000 kΩ to 1.000 kΩ
How it works
Resistor colour codes follow IEC 60062. Each colour band encodes a digit (0–9), a multiplier power of ten, a tolerance percentage, and (for 6-band precision resistors) a temperature coefficient. Reading the bands from the end closest to the lead, the first 2 (or 3) bands form the mantissa, the next band gives the multiplier, the tolerance band defines the accuracy class, and the optional 6th band specifies temperature stability in ppm/°C.
Formulas
4-band value
R = (10 × band1 + band2) × multiplier
5/6-band value
R = (100 × band1 + 10 × band2 + band3) × multiplier
Series
Series R = R1 + R2 + ... + Rn
Parallel
1/Rparallel = 1/R1 + 1/R2 + ...
Frequently Asked Questions
How do I tell which end of a resistor to read from?
Start from the band closest to a lead. The tolerance band (gold or silver for 4-band) is always at the opposite end. If in doubt, read both ways and look up both values — only one will be a standard E-series value.
Why do parallel resistors always give a smaller total?
Adding parallel paths gives current more ways to flow, reducing the total opposition. The result is always less than the smallest individual resistor.
What does 6-band mean?
6-band resistors add a temperature coefficient band, specifying how much the resistance drifts per degree Celsius. Used in precision circuits where thermal stability matters.
What are standard E-series resistor values?
The E12, E24, E48, E96 and E192 series define preferred values based on logarithmic spacing. For example, E12 values are: 1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2 (and their decade multiples).