Resistor Calculator & Ohms Law

The complete resistor toolkit for makers, students, hobbyists, and engineers.

Decode color bands, SMD codes, and run Ohm's Law calculations — all in one fast, beautifully designed app. No internet required, no ads, no tracking.

KEY FEATURES

- Color Band Decoder — Full support for 4, 5, and 6-band resistors. Tap any band to change its color and watch the value update instantly with tolerance range.
- Reverse Lookup — Enter a resistance value in Ω, kΩ, or MΩ and instantly see the matching color bands at your preferred tolerance (±1%, ±2%, ±5%, ±10%).
- SMD Code Decoder — Handles all four major formats: 3-digit (like 103 = 10 kΩ), 4-digit (like 1002 = 10 kΩ), R-notation (like 4R7 = 4.7 Ω), and precision EIA-96 codes (like 01A = 100 Ω).
- Ohm's Law Calculator — Calculate voltage, current, resistance, or power from any two known values. Every formula combination supported: V=IR, I=V/R, P=VI, P=V²/R, P=I²R.
- Favorites & History — Save frequently-used values to favorites. Recent calculations are kept in your history automatically.
- E-Series Standards — Visual indicators show when a value matches the standard E6, E12, or E24 series — perfect for BOM verification and component selection.
- Dark & Light Mode — Auto-adapts to your system theme. Easy on the eyes whether you're soldering at midnight or debugging in daylight.
- 10 Languages — English, Turkish, German, Spanish, French, Italian, Russian, Portuguese, Japanese, Chinese.

PERFECT FOR

- Electronics hobbyists and makers
- Engineering and electronics students
- Arduino, Raspberry Pi, and DIY enthusiasts
- Field technicians and repair professionals
- Educators teaching electronics
- Anyone working with through-hole or SMD resistors

Built with care by Deve Apps — software that respects you.