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.