OhmKit - Resistor Calculator

Decode resistor color codes and SMD markings, calculate Ohm’s law and LED circuits, and organize projects with BOM, PDF and CSV tools—in 13 languages.

OhmKit is a resistor calculator and electronics toolkit designed for engineers, technicians, students, makers, and electronics enthusiasts.

Decode resistor color codes and SMD markings, calculate circuit values, find suitable standard resistors, and organize your components and projects in one clean app.

CALCULATORS

• Decode 3, 4, 5, and 6-band resistor color codes • Convert resistance values into color bands • Decode and encode SMD resistor markings • Calculate series and parallel resistors • Find target resistance combinations using standard E-series values • Calculate voltage, current, resistance, and power with Ohm’s law • Design series and parallel LED circuits • Calculate voltage dividers • Calculate resistor power and recommended power ratings • Automatically convert engineering units

PROJECT TOOLS

• Save calculation history and favorites • Create reusable presets • Organize components into projects and bills of materials (BOM) • Export project data as PDF or CSV • Back up and restore supported local data • Copy and share calculation results • Access built-in electronics references

DESIGNED FOR EVERYDAY USE

• Clear circuit diagrams and standard electrical symbols • Light and dark themes • Adjustable calculator and display preferences • Interface available in 13 languages • Core calculations run locally on your device

The free version contains ads. OhmKit Pro removes ads and unlocks additional workflow features. Purchases are securely processed through the App Store.

Calculation results are provided as engineering aids. Always verify component ratings and manufacturer specifications before building or powering a circuit.