RESULTS
E6 Series (20% Tol.)
- Ω (-)
E12 Series (10% Tol.)
- Ω (-)
E24 Series (5% Tol.)
- Ω (-)
E48 Series (2% Tol.)
- Ω (-)
E96 Series (1% Tol.)
- Ω (-)
E192 Series (0.5% Tol.)
- Ω (-)
Detailed EIA Comparison Matrix
Compare the targeted value alongside standard EIA divisions to evaluate the absolute resistance deviation below:
| EIA Series |
Value (Ω) |
Error (%) |
| E6 (20% Tolerance) |
- |
- |
| E12 (10% Tolerance) |
- |
- |
| E24 (5% Tolerance) |
- |
- |
| E48 (2% Tolerance) |
- |
- |
| E96 (1% Tolerance) |
- |
- |
| E192 (0.5% Tolerance) |
- |
- |
Input Parameters Specification
Desired Resistance Value
The target resistance value in ohms (Ω) needed for your specific circuit design or analog calculation.
EIA Preferred Series
Geometrically spaced divisions (E6 to E192) that define standard commercial manufacturing values.
Tolerance Rating
The maximum allowable percentage deviation of a physical component from its nominal standard rating.
Percentage Error
The mathematical difference between your desired value and the closest commercially available standard resistor.
Practical Operational Examples
LED Driver Current Limiter
Your calculation indicates a 345 Ω resistor is needed to protect an LED. Entering 345 reveals that a 330 Ω is available in E6 (4.35% error) or 344 Ω in E192 (0.29% error).
Op-Amp Gain Set
An inverting operational amplifier requires a precise feedback ratio. Finding close matches in the E96 or E192 series ensures high-precision gain and negligible analog signal errors.
Voltage Divider Matching
When selecting resistors for microchip ADC voltage scaling, compare standard E12 and E24 values to evaluate the absolute output voltage error.
Switching Regulator Feedback
Calculate feedforward networks using E96 series values (1% tolerance) to meet standard power supply feedback specifications.
Diagrams & Theory
Resistors are not manufactured in simple linear increments (e.g., 10, 20, 30 Ω). Instead, they are spaced logarithmically to ensure that the ratio between consecutive values remains constant relative to the component's tolerance rating. This system is known as the Preferred Number Series or Renard Series.
Formulas & Mathematical Logic
Logarithmic Spacing Formula: Value = 10^(n/E)
Geometric Progression step factor: R_step = 10^(1/E)
Percentage Deviation (Error): Error = 100 x (R_closest - R_desired) / R_desired
For example, the E12 series divides each decade into 12 log steps, which are rounded to standard two-digit values. This ensures there are no overlapping tolerance zones between adjacent components.
Step-by-Step Selection Walkthrough
Example: Matching a target resistance of 5,500 Ω.
Step 1: Convert the value to its scientific base (mantissa): 5.5 x 10^3.
Step 2: Scan the E12 series values. The nearest steps are 4.7 (4700 Ω) and 5.6 (5600 Ω).
Step 3: Calculate the percentage error for 5,600 Ω: 100 x (5600 - 5500) / 5500 = +1.82%.
Step 4: Move to the E96 1% series to find a closer match of 5.49 kΩ with an error of only -0.18%.
About This Calculator
Find standard EIA values and error percentages instantly.
The CalcBoy Standard Resistor Calculator identifies nearest component values across E6, E12, E24, E48, E96, and E192 series, displaying deviation errors in real-time.
Designers must frequently adapt their theoretical math to utilize physical parts available in commercial inventories. Standard values are distributed across standardized logarithmic brackets to cover the entire resistance scale with minimal inventory overlaps.
This tool helps you evaluate whether a cheap, standard E24 (5% tolerance) resistor is sufficient for your circuit, or if the precision demands of your design necessitate stepping up to an E96 (1%) or E192 (0.5%) component to maintain adequate system performance.
Best UsePrototyping, analog gain networks, and divider matching.
Supported seriesComprehensive calculation for E6 to E192 standard lists.
Helpful ForEnsuring design accuracy on custom printed circuit boards.
Design ReminderAlways choose series specifications that align with your PCB thermal limits.
Tip: Standard metal film resistors generally feature 1% tolerances (E96 series), while carbon film resistors are typically offered at 5% tolerances (E24 series).
Frequently Asked Questions
1. What are E-series resistor standards?
E-series are standardized sets of preferred values established by the EIA (Electronic Industries Alliance). The number following the 'E' (e.g. E6, E24, E96) indicates the number of logarithmic steps within each decade.
2. Why are resistors spaced logarithmically instead of linearly?
Logarithmic spacing ensures that the percentage difference between consecutive values remains constant relative to the component's tolerance. This prevents gaps or redundant overlaps in manufacturing.
3. Which EIA series is most commonly used?
The E24 series (5% tolerance) is the standard for general-purpose carbon film resistors. The E96 series (1% tolerance) is widely used for precision metal film resistors in sensitive analog applications.
4. How is the standard resistor value error calculated?
The percentage error is calculated by dividing the difference between the standard value and your desired value by the desired value, then multiplying by 100.
5. What happens if my selected resistor value has too high of an error?
A high resistance error can cause circuit instabilities, such as drifting amplifier gains, shifted voltage divider nodes, or incorrect timing periods in oscillator networks.
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