Electronics Calculators
Ohm's Law, voltage drop, resistor, and electrical calculation tools
Electronics Calculators
Professional electrical and electronics calculators for engineers, technicians, and hobbyists. Calculate voltage, current, resistance, power, and component values with precision.
Calculate current limiting resistor values for LED circuits
How to use: Calculate current-limiting resistor for LED circuits to prevent burnout. Enter Source Voltage (power supply voltage), LED Forward Voltage (typical values: Red/Yellow 2.0-2.2V, Green/Blue/White 3.0-3.4V), LED Current in mA (standard 20mA, high-power up to 350mA), Number of LEDs, and Configuration (Series or Parallel). Results show: Required Resistor value, Standard Resistor (nearest E12/E24 series value), Power Rating (minimum wattage), and Configuration type. Formula: R = (Vsource - Vled) / Iled. Always use resistor rated for 2× calculated power minimum. Without proper resistor, LEDs fail instantly. Essential for Arduino projects, indicator lights, displays, and custom lighting.
Complete Electronics Calculator Suite
Professional-grade electrical and electronics calculators for engineers, technicians, students, and hobbyists. Calculate electrical parameters with precision using industry-standard formulas and methods.
Basic Electrical Laws
- • Ohm's Law calculator (V=IR)
- • Power calculations (P=VI, P=V²/R)
- • Current, voltage, resistance solving
- • Electrical parameter conversions
- • Circuit analysis tools
Voltage & Current
- • Voltage drop calculations
- • Wire gauge recommendations
- • Current capacity analysis
- • Power loss calculations
- • Circuit efficiency analysis
Component Calculations
- • Resistor color code decoder
- • Series/parallel combinations
- • LED current limiting resistors
- • Capacitor value calculations
- • Component tolerance analysis
Circuit Design
- • Wire sizing for applications
- • Voltage drop optimization
- • Power distribution planning
- • Safety factor calculations
- • Load analysis tools
LED & Lighting
- • LED resistor calculations
- • Forward voltage analysis
- • Current limiting design
- • Series vs parallel configuration
- • Power consumption optimization
Professional Tools
- • Engineering-grade precision
- • Industry standard formulas
- • Code compliance checking
- • Safety recommendations
- • Technical documentation