Standard Resistor Value Calculator

Find the exact IEC 60063 standard resistor value closest to your target. Supports E6, E12, E24, E48, E96 series — with error analysis, color code, and component selection guidance.

? 1 kΩ
? 4.7 kΩ
? 10 kΩ
⚡ 220 Ω
? 100 kΩ
?️ 1 MΩ
No server processing — All calculations run locally. Your designs stay private.

Understanding Standard Resistor Values & E‑Series

In electronic design, resistors are manufactured according to preferred numbers defined by IEC 60063. The E‑series (E6, E12, E24, E48, E96, E192) defines geometric progressions that allow manufacturers to cover the entire resistance range with minimal inventory while guaranteeing tolerance intervals. Choosing the correct E‑series ensures cost-efficiency and avoids non‑stock parts.

Why E‑series matter: Each E‑series step multiplies by 10^(1/n) where n = number of values per decade. For E24, n=24, step ≈ 1.1; for E96, step ≈ 1.024. Higher series yield finer resolution but higher cost.

How our calculator works

After converting your target to Ohms, the algorithm computes the nearest value from the selected E‑series standard table (1–10 decade base). It identifies the optimal exponent and compares distances across the whole decade range, returning the closest standard value along with the theoretical error. The tool also displays the two adjacent standard values (lower/higher) for tolerance stack analysis. The color code is generated per IEC 60062:2020.

Choosing the right tolerance

  • E6 (20%) – general purpose, legacy circuits, low precision.
  • E12 (10%) – basic consumer electronics, signal paths.
  • E24 (5%) – most common for hobbyist and industrial designs.
  • E48 (2%) – measurement & audio equipment.
  • E96 (1%) / E192 (0.5%) – precision analog, medical, instrumentation.
Practical case 1: Op‑amp feedback network

Design a non‑inverting amplifier with gain of 10 using standard resistors. If R1 = 1 kΩ (E24), then R2 should be 9 kΩ. The nearest E24 value to 9 kΩ is 9.1 kΩ (error +1.1%). For a precision instrumentation amplifier requiring exact gain, switch to E96 series: 9.09 kΩ (error only 0.1%) or combine two resistors in series/parallel. This tool quickly shows the trade‑off between accuracy and component availability.

Practical case 2: I²C pull‑up resistors

I²C bus specification recommends pull‑up resistors between 1 kΩ and 10 kΩ depending on bus capacitance and speed. Common standard values used: 1.2 kΩ, 1.5 kΩ, 2.2 kΩ, 4.7 kΩ, and 10 kΩ. Our calculator can verify which standard value is closest to your calculated optimum (e.g., 1.8 kΩ ideal → closest E24 is 1.8 kΩ exactly, error 0%).

Understanding resistor color code and SMD marking

This tool displays both 4‑band (for E6/E12/E24) and 5‑band (for E48/E96) color codes. For surface‑mount devices (SMD), standard 3‑digit or 4‑digit codes are used — the underlying standard resistance value is identical. Example: 4.7 kΩ is marked "472" (47 × 10²). Use this calculator to obtain the numeric value, then refer to manufacturer SMD marking tables.

Power rating and temperature coefficient (TCR) reminder

Selecting the correct standard value is only part of the design. Always verify that the resistor can dissipate the required power (P = I²R or V²/R) without exceeding its rating. Common through‑hole resistors are 1/4W or 1/2W; SMD sizes (0402, 0603, 0805) have lower ratings. Also check TCR (ppm/°C) for precision circuits — E96 series resistors often offer lower TCR (25 or 50 ppm). This calculator focuses on value matching; additional derating must be done by the engineer.

Standard E‑series reference table (decade 1–10)

E6 E12 E24 E48 (excerpt) E96 (excerpt)
1.0, 1.5, 2.2, 3.3, 4.7, 6.8 1.0,1.2,1.5,1.8,2.2,2.7,3.3,3.9,4.7,5.6,6.8,8.2 1.0,1.1,1.2,1.3,1.5,1.6,1.8,2.0,2.2,2.4,2.7,3.0,3.3,3.6,3.9,4.3,4.7,5.1,5.6,6.2,6.8,7.5,8.2,9.1 1.00,1.05,1.10,1.15,1.21,1.27,1.33,1.40,1.47,1.54,1.62,1.69,1.78,1.87,1.96,2.05,2.15,2.26,2.37,2.49,2.61,2.74,2.87,3.01,3.16,3.32,3.48,3.65,3.83,4.02,4.22,4.42,4.64,4.87,5.11,5.36,5.62,5.90,6.19,6.49,6.81,7.15,7.50,7.87,8.25,8.66,9.09,9.53 1.00,1.02,1.05,1.07,1.10,1.13,1.15,1.18,1.21,1.24,1.27,1.30,1.33,1.37,1.40,1.43,1.47,1.50,1.54,1.58,1.62,1.65,1.69,1.74,1.78,1.82,1.87,1.91,1.96,2.00,2.05,2.10,2.15,2.21,2.26,2.32,2.37,2.43,2.49,2.55,2.61,2.67,2.74,2.80,2.87,2.94,3.01,3.09,3.16,3.24,3.32,3.40,3.48,3.57,3.65,3.74,3.83,3.92,4.02,4.12,4.22,4.32,4.42,4.53,4.64,4.75,4.87,4.99,5.11,5.23,5.36,5.49,5.62,5.76,5.90,6.04,6.19,6.34,6.49,6.65,6.81,6.98,7.15,7.32,7.50,7.68,7.87,8.06,8.25,8.45,8.66,8.87,9.09,9.31,9.53,9.76
Values according to IEC 60063:2015. For full E192 series, see reference literature.
Authoritative references & further reading:
Last verification against IEC 60063: May 2026. This tool implements the full E6/E12/E24/E48/E96 series as defined by the international standard. No user data is collected or transmitted.

Frequently Asked Questions

The calculator automatically picks the nearest value from the selected E‑series. The error percentage tells you the mismatch. For critical circuits, use E96/E192 to minimize deviation.

E24 and lower series typically use 4‑band code (two significant digits + multiplier + tolerance). E48/E96 use 5‑bands (three significant digits) due to higher precision. Our tool selects automatically based on the matched value's effective digits.

SMD resistors often use 3‑digit or 4‑digit codes, but the standard resistance value is identical. This tool gives the numeric value; you can then look up the corresponding SMD marking table.

Error is computed as |(R_standard - R_target)| / R_target × 100%. It is pure theoretical mismatch — actual component tolerance adds additional variation.

This calculator finds the correct resistance value only. You must independently verify that the selected resistor meets your power dissipation and temperature coefficient requirements based on the datasheet.