Resistor Code & Value Calc

Resistor color code: decode nominal resistance and encoded tolerance from the markings you enter. Resistor Code & Value Calculator is a focused manual reference for nominal resistance, encoded tolerance and supported SMD markings.

FREE CORE TOOLS
• Decode 3- and 4-band resistors with named colors and clear band roles.
• See the nominal value, tolerance interval and arithmetic. Three-band tolerance is explicitly assumed, rather than encoded.
• Convert Ω, kΩ and MΩ and browse common E12/E24 preferred values.
• Save up to 20 new recent readings with labels and notes. Search, reopen, duplicate, delete and undo.
• Export JSON backups, CSV and readable text. Import JSON backups without silently truncating existing or imported work at the Free limit.
• Use light, dark or system appearance. Core calculations and local records work offline.

OPTIONAL LIFETIME PRO
A one-time paid upgrade adds:
• 5- and 6-band decoding, including explicit temperature coefficients.
• Reverse value-to-band lookup that keeps your target while you compare exact supported encodings.
• Supported 3/4-digit numeric and 3/4-character R decimal SMD codes, such as 103, 4R7 and 0R1. Zero-ohm numeric markings are supported. EIA-96 and manufacturer suffixes are not included.
• Unlimited new history, saved presets, comparison of 2–4 readings and PDF reference sheets.

No ads and no subscription in either version. Existing saved work remains readable, its labels and notes editable, deletable and available for basic export if Pro is unavailable. New advanced work requires Pro. Google Play purchase and restore need a connection; previously verified ownership can be used offline until a successful ownership check changes it.

YOUR LOCAL BENCH RECORD
Readings retain raw markings, exact values, notes and calculation-version information. There is no PatchMedia account or cloud sync. Choose your own backup destination with Android’s document picker. Exported files are unencrypted and may be synchronized by your chosen provider. Purchase ownership, settings and private review authorization are excluded from portable backups. Google Play handles payment services and technical Billing diagnostics; details are in the privacy policy.

MANUAL REFERENCE SCOPE
Choose bands or enter a supported marking yourself. There is no camera/OCR or physical component measurement. Results describe nominal marking arithmetic; they do not determine circuit suitability, power rating or repair authorization. Nonstandard, faded or reversed markings may be ambiguous. Check the component’s documented marking when unsure.

Use this resistor calculator for a workbench study session when comparing options such as Electrodoc - electronics tools. A resistor color code example can become a labeled practice record for learning the band order, without claiming the part has been tested.

Recent changes:
First release of Resistor Code & Value Calculator.
Decode 3/4-band resistors, convert SI units, and keep local readings with JSON backup, CSV and text export. Optional lifetime Pro adds 5/6-band decoding, reverse lookup, supported numeric/R SMD codes, presets, comparison and PDF sheets. Manual reference arithmetic only.