Resistor Calculator & Ohms Law

v1.3: Capacitor color codes + numeric decoder (104, 4R7)! Plus all-new band visualization, tap-to-open from saved values. 7 calculators in one offline app.

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.

PRIVACY FIRST

This app has no ads, no analytics, no tracking, and no internet connection. Everything works locally on your device. We don't collect data because we don't want it.

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.