SMD Resistor Code Calculator
3-Digit, 4-Digit & EIA-96 Decoder
Instantly decode any SMD resistor code — 3-digit EIA, 4-digit EIA, or EIA-96 format. Our free SMD resistor code calculator identifies the exact resistance value, tolerance range, and code type from the markings printed on the chip resistor body.
What is an SMD Resistor Code?
Understanding SMD Resistor Markings — 3-Digit, 4-Digit & EIA-96
SMD (Surface Mount Device) resistors are too small to use colour bands like through-hole resistors. Instead, a numeric or alphanumeric code is printed directly on the resistor body to indicate its resistance value. The SMD resistor code calculator below decodes all three standard formats — 3-digit EIA (most common), 4-digit EIA (precision), and EIA-96 (high-precision E96 series) — giving you the exact resistance value, tolerance, and min/max range instantly.
3-Digit EIA Code
The most common SMD resistor marking. Two significant digits followed by a multiplier digit. Used on general-purpose 0805, 0603, 0402 package resistors with ±5% or ±20% tolerance.
102 = 10 × 10² = 1kΩ4-Digit EIA Code
Three significant digits plus a multiplier. Used on precision resistors with ±1% or better tolerance. Common on 0805, 1206 package components in professional PCB designs.
1002 = 100 × 10² = 10kΩEIA-96 Code
A 2-digit number (01–96) from the E96 series lookup table plus a letter multiplier. Used on 1% tolerance high-precision resistors, common in 0402 and 0201 packages where space is critical.
01A = 100 × 1 = 100ΩFree Online SMD Tool
SMD Resistor Code Calculator — Decode Any Marking
Enter the code printed on your SMD resistor below. Select the code type — 3-digit, 4-digit, or EIA-96 — and our SMD resistor value calculator instantly decodes the exact resistance, tolerance, minimum, and maximum values. Supports the R-notation for sub-10Ω values (e.g. 4R7 = 4.7Ω) and the 000/0000 jumper code.
SMD Resistor Code Calculator
Decode 3-digit, 4-digit EIA and EIA-96 SMD resistor codes instantly.
Decode Guide
How to Read SMD Resistor Codes — All 3 Formats
A complete guide to decoding every SMD resistor code — 3-digit EIA, 4-digit EIA, and EIA-96 — with formulas, examples, and the full lookup table.
Formula & Examples
D1 and D2 are significant digits. M is the multiplier exponent. R replaces the decimal point for sub-10Ω values. 000 = 0Ω jumper.
4R7 = 4.7 Ω (R = decimal)
000 = 0 Ω (Jumper)
Formula & Examples
Three significant digits plus a multiplier. Used on ±1% precision resistors where one extra significant figure matters. 0000 = 0Ω jumper.
10R0 = 10.0 Ω
0000 = 0 Ω (Jumper)
Formula & Examples
NN = 2-digit index (01–96) from the E96 table. L = letter multiplier. Used on ±1% high-precision 0402 and 0201 package resistors.
96F = 976 × 100K = 97.6 MΩ
50C = 324 × 100 = 32.4 kΩ
The suffix letter in an EIA-96 code sets the multiplier applied to the table base value.
Find your 2-digit code below and multiply its base value by your letter multiplier above.
FAQ
Frequently Asked Questions — SMD Resistor Code Calculator
Direct answers to the most common questions about SMD resistor codes, EIA-96, and how to decode chip resistor markings.
To read an SMD resistor code, first count the characters to identify the format. Three numeric characters = 3-digit EIA: the first two digits are significant figures and the third is the power-of-10 multiplier. For example, 472 = 47 × 10² = 4,700Ω (4.7kΩ). Four numeric characters = 4-digit EIA: the first three are significant figures and the fourth is the multiplier. For example, 4702 = 470 × 10² = 47kΩ. Two digits + a letter = EIA-96: look up the base value from the E96 table (01–96) and multiply by the letter factor. For example, 01A = 100 × 1 = 100Ω. If R appears in the code, it acts as a decimal point — 4R7 = 4.7Ω. Use our free SMD resistor code calculator above to decode any code instantly.
A 3-digit SMD resistor code uses two significant figures plus a multiplier digit, providing lower precision — typically used on ±5% or ±20% tolerance resistors (E24 and E12 series). A 4-digit SMD resistor code uses three significant figures plus a multiplier digit, enabling one extra decimal place of precision — used on ±1% tolerance resistors (E96 series) in professional PCB designs.
For example, a 3-digit code can only express 4,700Ω as 472, while a 4-digit code can express 4,750Ω as 4751. On space-constrained packages like 0402 and 0201, the EIA-96 format is used instead of 4-digit codes to keep the marking compact while still identifying E96 series values precisely.
In an SMD resistor code, the letter R acts as the decimal point for values below 10 Ohms. This notation is used because a decimal point (.) is too small and easily missed on a tiny surface mount component. For example, 1R0 = 1.0Ω, 4R7 = 4.7Ω, R47 = 0.47Ω, and 10R = 10Ω. The R-notation can appear in both 3-digit and 4-digit SMD resistor codes. It is part of the IEC 60062 marking standard used worldwide for passive components.
The EIA-96 SMD resistor code is a compact 3-character marking system used on precision ±1% surface mount resistors from the E96 value series. The format is: two digits (01–96) indicating the base resistance from a fixed lookup table, followed by a letter (A/B/C/D/E/F/H/R/S/X/Y/Z) indicating the multiplier.
The E96 series contains 96 standard resistance values per decade, and the EIA-96 coding allows all of them to be expressed in just 3 characters — ideal for tiny 0402 and 0201 package resistors. For example, 01A = 100×1 = 100Ω, 96F = 976×100,000 = 97.6MΩ. Use the EIA-96 tab in our SMD resistor calculator above to decode any EIA-96 code using the full 96-value lookup table.
An SMD resistor marked 000 (3-digit) or 0000 (4-digit) is a zero-ohm resistor, also called a jumper resistor or zero-ohm link. It has effectively 0Ω resistance (typically under 50mΩ in practice) and is used as a wire link in PCB design to connect two points on the board that cannot be directly connected due to routing constraints.
Zero-ohm resistors are placed using standard SMD pick-and-place assembly machines, making them useful for bridging traces across layers, creating optional connections for different product configurations, or providing a convenient solder point for rework and debugging. They appear on the BOM as standard 0402, 0603, or 0805 resistors and do not require any special assembly process.
SMD resistor package size determines which code format is practically usable. Large packages (2512, 2010, 1812, 1210, 1206) have enough space for 3-digit or 4-digit codes. Standard packages (0805, 0603) typically use 3-digit codes for ±5% and 4-digit codes for ±1% resistors. Smaller packages (0402) use EIA-96 coding for ±1% resistors because 4 characters are too small to print clearly. Very small packages (0201, 01005) are often unmarked entirely due to physical size constraints.
When working with unlabeled or unclear SMD resistors in a PCB, use a multimeter to measure resistance in-circuit (with power off) or desolder the component and measure it independently for accurate identification.
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