Resistor Color Code Chart (4-Band and 5-Band) with Tolerance Table

What You Need to Know

Resistor color codes let you read a resistor’s nominal resistance and tolerance directly from colored bands—fast and reliable when the printed value is missing (common in through-hole resistors used in DC circuits).

Core rule: each band encodes either a digit, a multiplier (power of 10), or a tolerance.

• 4-band resistor: $\text{(2 significant digits)}\; +\; \text{multiplier}\; +\; \text{tolerance}$
• 5-band resistor: $\text{(3 significant digits)}\; +\; \text{multiplier}\; +\; \text{tolerance}$

Why it matters in DC circuits: you’ll constantly need to confirm component values for voltage dividers, bias networks, current limiting, and pull-up/pull-down resistors—often under time pressure.

Critical reminder: the color code gives a nominal value and a range set by tolerance; the actual resistance can fall anywhere in that range.

Step-by-Step Breakdown

A. Identify reading direction (don’t start from the tolerance band)

1. Find the tolerance band (almost always the last band):
   • Common tolerance colors: Gold (±5%), Silver (±10%), Brown (±1%), Red (±2%).
   • The tolerance band is often spaced farther from the other bands.
2. Read from the opposite end toward the tolerance band.

B. Decide: 4-band or 5-band

1. Count the bands.
2. Apply the correct structure:
   • 4-band: digit–digit–multiplier–tolerance
   • 5-band: digit–digit–digit–multiplier–tolerance

C. Convert bands to a value

1. Convert the first $2$ (or $3$) bands to significant digits.
2. Convert the multiplier band to a factor $10^n$.
3. Compute the nominal resistance:
   • 4-band:
     $R = (10\,d_1 + d_2)\times 10^{m}$
   • 5-band:
     $R = (100\,d_1 + 10\,d_2 + d_3)\times 10^{m}$

D. Apply tolerance to get the min/max range

If tolerance is $\pm t\%$:

• $R_{\min} = R\left(1 - \frac{t}{100}\right)$
• $R_{\max} = R\left(1 + \frac{t}{100}\right)$

Quick worked micro-example (4-band)

Bands: Yellow – Violet – Red – Gold

1. Digits: Yellow $=4$, Violet $=7$ → $47$
2. Multiplier: Red $=10^2$
3. Nominal: $R=47\times 10^2=4700\,\Omega=4.7\,k\Omega$
4. Tolerance: Gold $=\pm 5\%$
5. Range: $R_{\min}=4.7\,k\Omega\times 0.95=4.465\,k\Omega$, $R_{\max}=4.7\,k\Omega\times 1.05=4.935\,k\Omega$

Key Formulas, Rules & Facts

A. Resistance calculation + tolerance range

B. Digit color chart (significant figures)

These colors map to digit values $0\text{–}9$.

C. Multiplier color chart

Multiplier band means “multiply the significant digits by $10^{m}$.”

Gold/silver as multipliers are common in low-ohm (sub-$10\,\Omega$) resistors.

D. Tolerance table (the “last band”)

Typical practical pattern:

• Many general-purpose resistors are 4-band with Gold (±5%) or Silver (±10%).
• Many precision resistors are 5-band with Brown (±1%) or Red (±2%).

E. How to tell 4-band vs 5-band quickly

• 4-band: often used for $\ge 5\%$ tolerance; only $2$ significant digits.
• 5-band: often used for $\le 2\%$ tolerance; $3$ significant digits.

Edge case: some resistors have 6 bands (extra band for temperature coefficient). If you see $6$ bands, read the first $5$ like a 5-band resistor; the last band is not tolerance (it’s tempco). Don’t let that derail your 4/5-band decoding.

Examples & Applications

Example 1 (4-band, common kΩ value)

Bands: Brown – Black – Orange – Gold

• Digits: Brown $=1$, Black $=0$ → $10$
• Multiplier: Orange $=10^3$
• Nominal: $R=10\times 10^3=10000\,\Omega=10\,k\Omega$
• Tolerance: Gold $=\pm 5\%$
• Range: $R_{\min}=10\,k\Omega\times 0.95=9.5\,k\Omega$, $R_{\max}=10\,k\Omega\times 1.05=10.5\,k\Omega$

Example 2 (5-band, precision value)

Bands: Brown – Black – Black – Red – Brown

• Digits: Brown $=1$, Black $=0$, Black $=0$ → $100$
• Multiplier: Red $=10^2$
• Nominal: $R=100\times 10^2=10000\,\Omega=10\,k\Omega$
• Tolerance: Brown $=\pm 1\%$
• Range: $9.9\,k\Omega$ to $10.1\,k\Omega$

Exam angle: this looks like Example 1’s nominal value, but the band count and tolerance tell you it’s a precision resistor.

Example 3 (4-band, low-ohm with gold multiplier)

Bands: Red – Red – Gold – Gold

• Digits: $22$
• Multiplier: Gold $=10^{-1}$
• Nominal: $R=22\times 10^{-1}=2.2\,\Omega$
• Tolerance: Gold $=\pm 5\%$

Exam angle: students often misread the third band gold as tolerance; in 4-band it’s the multiplier.

Example 4 (5-band, value not a “round decade”)

Bands: Yellow – Violet – Black – Brown – Red

• Digits: Yellow $=4$, Violet $=7$, Black $=0$ → $470$
• Multiplier: Brown $=10^1$
• Nominal: $R=470\times 10^1=4700\,\Omega=4.7\,k\Omega$
• Tolerance: Red $=\pm 2\%$

Exam angle: same nominal as a common 4-band value, but encoded with $3$ significant digits (470 vs 47) for precision series parts.

Common Mistakes & Traps

1. Reading from the wrong end

   • What goes wrong: you start at the tolerance band and decode backward.
   • Why wrong: the tolerance band is meant to be last; reversing changes the number completely.
   • Fix: locate the spaced band (often gold/silver/brown) and read toward it.

2. Confusing 4-band vs 5-band structure

   • What goes wrong: you treat a 5-band resistor as 4-band (or vice versa).
   • Why wrong: you’ll shift digit/multiplier positions.
   • Fix: count bands first, then apply: $2$ digits for 4-band, $3$ digits for 5-band.

3. Mixing up multiplier vs tolerance gold/silver

   • What goes wrong: you see gold and assume tolerance, even when it’s the 3rd/4th band.
   • Why wrong: gold/silver can be multiplier (especially in 4-band low-ohm parts).
   • Fix: determine band position by count: in 4-band, band 3 is multiplier; in 5-band, band 4 is multiplier.

4. Forgetting “no band” tolerance exists

   • What goes wrong: you assume a missing tolerance band means you can’t decode it.
   • Why wrong: no band means $\pm 20\%$.
   • Fix: if there are only $3$ bands visible on an older resistor, it’s often a 4-band with no tolerance band.

5. Digit-color confusion (especially violet/gray/white in bad lighting)

   • What goes wrong: violet vs gray vs blue looks similar on worn parts.
   • Why wrong: a one-digit error can change value by large amounts.
   • Fix: use context (expected E-series values), and if possible confirm with a meter.

6. Misplacing the decimal mentally

   • What goes wrong: you compute digits correctly but misapply multiplier (e.g., $47\times 10^2$ as $47\,\Omega$).
   • Why wrong: multiplier is a power of ten shift.
   • Fix: rewrite as scientific notation: $47\times 10^2=4.7\times 10^3\,\Omega$.

7. Assuming tolerance equals measurement error of your multimeter

   • What goes wrong: you treat the tolerance band as the meter’s accuracy.
   • Why wrong: tolerance is the resistor’s manufacturing range, separate from instrument accuracy.
   • Fix: treat measured values as: actual resistor value ± meter accuracy; compare to tolerance range.

8. Ignoring that tolerance affects circuit behavior

   • What goes wrong: you design with nominal values only.
   • Why wrong: worst-case divider ratios or bias currents can shift.
   • Fix: use $R_{\min}$ and $R_{\max}$ for quick worst-case checks.

Memory Aids & Quick Tricks

Practical tip: if the value you decode isn’t close to a common series number (like $10\,k\Omega$, $4.7\,k\Omega$, $330\,\Omega$), re-check band order and digit colors.

Quick Review Checklist

• You can state the layouts:
  • 4-band: $d_1\,d_2\,\times 10^m\,\pm t\%$
  • 5-band: $d_1\,d_2\,d_3\,\times 10^m\,\pm t\%$
• You always locate the tolerance band first (last band, often spaced).
• You know the digit chart Black $0$ → White $9$.
• You know multiplier powers including Gold $10^{-1}$ and Silver $10^{-2}$.
• You know key tolerances: Brown $\pm 1\%$, Red $\pm 2\%$, Gold $\pm 5\%$, Silver $\pm 10\%$, None $\pm 20\%$.
• You can compute ranges using:
  • $R_{\min} = R\left(1 - \frac{t}{100}\right)$
  • $R_{\max} = R\left(1 + \frac{t}{100}\right)$
• You can sanity-check units (Ω vs kΩ vs MΩ) and spot impossible readings.

You’ve got this—decode a handful of examples quickly and the pattern becomes automatic.