Common Resistor Values: E12, E24, E96 Series, Tolerances, Brands, Models, Applications

User question

common resistor values

Artificial Intelligence Response

Direct answer to the question

• Commercial resistors come in preferred-number series (IEC 60063) called the E-series.
• The three series you will meet 99 % of the time are:
  • E12 (±10 %), 12 values/decade: 1.0 – 1.2 – 1.5 – 1.8 – 2.2 – 2.7 – 3.3 – 3.9 – 4.7 – 5.6 – 6.8 – 8.2
  • E24 (±5 %), adds the mid-values: 1.1 – 1.3 – 1.6 – 2.0 – 2.4 – 3.0 – 3.6 – 4.3 – 5.1 – 6.2 – 7.5 – 9.1
  • E96 (±1 %), 96 values/decade (e.g. 100 Ω, 102 Ω, 105 Ω … 976 Ω, 988 Ω).
• Each base value is multiplied by powers of ten (… 0.47 Ω, 4.7 Ω, 47 Ω, 470 Ω, 4.7 kΩ, 47 kΩ, … ).
• “Bench-stock” parts a designer actually pulls most often (through-hole or 0603 SMD):
  10 Ω, 22 Ω, 47 Ω, 100 Ω, 220 Ω, 330 Ω, 470 Ω, 680 Ω,
  1 k Ω, 1.5 k Ω, 2.2 k Ω, 3.3 k Ω, 4.7 k Ω, 6.8 k Ω, 10 k Ω, 22 k Ω, 47 k Ω, 100 k Ω, 220 k Ω, 470 k Ω, 1 M Ω.

Detailed problem analysis

1. Why preferred numbers?
   • A resistor marked 47 kΩ ±5 % can be anywhere between 44.65 kΩ and 49.35 kΩ.
   • The next E24 value, 51 kΩ, starts at 48.45 kΩ—so ranges overlap and there are no “holes.”
   • Producing every integer value would explode inventories; the geometric progression keeps logistics sane.

2. Mathematical basis
   • Within one decade (10× change in value) the n-th value of an E-series is
   \[ R_n = 10^{\,\frac{n}{E}} \;\; (n=0 … E-1) \]
   • Spacing between adjacent E12 values ≈ 21 %, E24 ≈ 10 %, E96 ≈ 2 %.

3. Complete IEC 60063 table (first decade, rounded to two sig-figs)
   • E3: 1.0 2.2 4.7
   • E6: 1.0 1.5 2.2 3.3 4.7 6.8
   • E12: + values shown above
   • E24: + values shown above
   • E48/E96/E192: progressively finer steps, used for ±2 %, ±1 %, ±0.5 %/0.25 %/0.1 %.

4. Decade multiplication
   Multiplying by 10ⁿ gives the full catalog from milliohms (current-shunts) to hundreds of megohms (electrometers).

5. Application “clusters”
   Pull-ups: 4.7 kΩ, 10 kΩ, 47 kΩ
   LED limiters (5 V logic): 220 Ω, 330 Ω, 470 Ω
   Timing RC (audio & µC reset): 10 kΩ // 100 nF, 100 kΩ // 1 µF
   Gain-setting op-amp: 1 kΩ-10 kΩ range (low noise), 10 kΩ-100 kΩ (low power)

Current information and trends

• Thin-film SMD resistors dominate new designs; 0.1 % tolerance at 25 ppm/°C in 0402/0603 are commodity items (Yageo RC series, Vishay CRCW-F, KOA RN**F).
• Metal-foil and bulk metal parts reach 0.005 % / 0.2 ppm/°C for metrology (VPG VHP/T hermally stable series).
• High-power shunt resistors (≤ 1 mΩ, 3–10 W) enable EV and server power-train current sensing.
• Digital potentiometers (I²C/SPI) offer 128–1024 taps replacing large E96 bins in adaptive designs.

Supporting explanations and details

• Combining resistors:
  • Series for additive values (e.g. 3.3 kΩ + 1.5 kΩ = 4.8 kΩ)
  • Parallel for lowering resistance: \(R_{eq} = \frac{R_1 R_2}{R_1+R_2}\).
• Tolerance stack-up: when two identical ±1 % resistors form a divider, the ratio error is ≈ √2 · 1 % ≈ 1.4 %.
• Temperature coefficient (TCR) matters more than nominal tolerance in precision analog; 25–50 ppm/°C is the sweet spot for instrumentation.

Ethical and legal aspects

• RoHS / REACH: modern resistors must be lead-free (Pb < 0.1 %).
• Counterfeit components: gray-market lots may be re-marked surplus with wrong tolerances → always buy from franchised distributors.
• E-waste: designers should avoid exotic values that hinder recycling or require custom parts that become obsolete quickly.

Practical guidelines

1. Lab starter kit (through-hole): stock every E12 value from 10 Ω to 1 MΩ (96 parts) at ¼ W.
2. Production BOM: pick the highest tolerance your circuit can accept; it halves cost and shortens lead time.
3. Prefer values that appear in multiple packages and power ratings (e.g., 4.7 kΩ exists in 0201 to 2512, 1⁄16 W to 3 W).
4. For “pesky” values (14 kΩ, 23.2 kΩ) either:
   • step up to E96;
   • trim with a potentiometer;
   • use a two-resistor network.
5. Verify availability early—some exotic E96/E192 chips become NRND even though “standard” in theory.

Possible disclaimers or additional notes

• Datasheet tolerance applies at 25 °C, no load. Self-heating or cold-solder joints can shift value significantly.
• High-voltage (>200 V) or pulse applications need voltage-coefficient data; ordinary 0603 parts may arc at ~150 V.

Suggestions for further research

• IEC 60115-8 (thin-film resistors) and IEC 60115-4 (wirewound) reliability standards.
• Vishay “Application Note 26” on resistor stability versus time and temperature.
• Study Kelvin-sense layouts for sub-10 mΩ current shunts.
• Investigate “resistor ladder” networks in DACs for matching strategies.

Brief summary

Resistor manufacturers follow the IEC 60063 E-series to keep inventories manageable and ensure overlap of tolerances. E12 and E24 cover almost all hobbyist and general-industry needs; E96 and above serve precision work. Multiplying the base numbers by 10ⁿ yields the full catalog from sub-ohm shunts to multi-megohm insulation resistors. Knowing these series, their tolerances, and practical availability lets you pick economical, reliable parts—or combine them—without reinventing the wheel each time you need “just a resistor.”

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.