SMD Capacitor Code Calculator

Decode EIA 3-digit, letter+digit (EIA-198) and R-decimal capacitor markings on chips and tantalums to real capacitance.

Code on the packageMarking system

47 µF

Capacitance

47 M

47000

µF

Worked example — with your numbers

digits 47 × 10^6 = 47000000 pF

3-digit: C(pF) = DD × 10^d ; EIA-198: C(pF) = letter-mantissa × 10^d

References: EIA-198 (capacitor marking standard) · IEC 60062:2016 (marking codes for R & C)

Most small MLCCs carry no marking at all — you must measure (LCR meter) or trust the reel. Tantalum chips additionally mark voltage with a letter (e.g. “A” = 10 V on Kemet parts) and polarity with a bar on the POSITIVE end — opposite of aluminium electrolytics. Same 3-digit code is also used on through-hole ceramics; a trailing letter there is tolerance (J = ±5 %, K = ±10 %, M = ±20 %).

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SMD Capacitor Code Calculator computes the capacitance behind chip/tantalum markings — EIA 3-digit, letter+digit and R-decimal — free, instant and private in your browser. Rework techs identifying tantalums and anyone facing a mystery chip cap use it to skip the datasheet algebra: type your numbers, read the answer with the substituted formula shown step by step, and share an exact permalink of the calculation.

About SMD Capacitor Code Calculator

SMD Capacitor Code Calculator computes the capacitance behind chip/tantalum markings — EIA 3-digit, letter+digit and R-decimal using the standard engineering relation: 3-digit: DD × 10^d pF; EIA-198: letter mantissa × 10^digit pF; 4R7 style puts the decimal at R. Worked live: '476' on a tantalum is 47 × 10⁶ pF = 47 µF; 'S5' decodes to 4.7 × 10⁵ pF = 470 nF. The result recalculates on every keystroke, the worked-example panel shows your numbers substituted into the formula, and the Copy permalink button encodes the inputs in the URL so a colleague opens exactly your calculation. Everything runs client-side — nothing you type leaves your device.

How to use SMD Capacitor Code Calculator

1Enter your values — the tool starts with realistic defaults for this exact use case, so the worked example is meaningful immediately.
2Read the live result and the worked-example panel, which substitutes your numbers into the formula step by step.
3Adjust any input to compare scenarios, then use Copy result or Copy permalink to share the calculation.

Why use SMD Capacitor Code Calculator?

✓Implements the real formula — 3-digit: DD × 10^d pF — with the substitution shown, not a black box
✓Built for rework techs identifying tantalums and anyone facing a mystery chip cap
✓Copy result and permalink buttons — share the exact calculation in a README, forum answer or design review
✓100% free, no sign-up, runs entirely in your browser (works offline once loaded)

Frequently asked questions

How do you calculate smd capacitor code?+

The capacitance behind chip/tantalum markings — EIA 3-digit, letter+digit and R-decimal follows 3-digit: DD × 10^d pF; EIA-198: letter mantissa × 10^digit pF; 4R7 style puts the decimal at R. For example, '476' on a tantalum is 47 × 10⁶ pF = 47 µF; 'S5' decodes to 4.7 × 10⁵ pF = 470 nF. The calculator applies the same relation and shows the substituted arithmetic so you can verify every step.

Which end of a tantalum chip is positive?+

The end with the BAR is positive — the opposite of aluminium electrolytics, and the single most common rework polarity mistake. Reversed tantalums fail short, often ignite, and they do it some hours later just to embarrass you.

Why are most MLCC chips completely blank?+

There's no room and marking costs money: 0402/0201 ceramics ship unmarked by design. Identification routes are the reel label, the BOM, or an LCR meter — and remember in-circuit readings include everything in parallel.

Is the SMD Capacitor Code Calculator free and private?+

Yes — completely free with no sign-up or usage limits, and it runs entirely in your browser: the values you enter are never uploaded or stored on a server.

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