Electronics Calculators
& Conversion Tools
Free, accurate electronics calculators built for PCB designers, engineers, and students. No sign-up required — just enter your values and get results instantly.
Pick a Calculator
Each tool is built to IEC or IPC standards and works on mobile, tablet, and desktop — no installation needed.
Ohm's Law Calculator
Enter any two known values — Voltage, Current, Resistance, or Power — and instantly calculate all four quantities. Supports all six formula combinations including P = I²R and P = V²/R.
Open CalculatorResistor Color Code Calculator
Decode any through-hole resistor instantly. Select band colours for 4-band, 5-band, or 6-band resistors. Displays resistance value, tolerance %, temperature coefficient, and min/max range.
Open CalculatorSMD Resistor Code Calculator
Decode 3-digit EIA, 4-digit EIA, and EIA-96 SMD chip resistor markings in real time. Includes the full EIA-96 lookup table (01–96), R-notation decimal support, and zero-ohm jumper detection.
Open CalculatorPCB Trace Width Calculator
Calculate the minimum copper trace width for internal and external PCB layers per IPC-2221 standard. Outputs trace width (mil/mm), resistance, voltage drop, and power loss for both layers simultaneously.
Open CalculatorDecimal & Fraction Converter
Convert decimals to fractions and fractions to decimals — including repeating (recurring) decimals, inch fractions down to 1/64", binary fractions, and percentages. Includes a decimal-fraction-percent reference chart.
Open CalculatorNew calculators added regularly
We are building more free electronics tools — voltage divider, capacitor charge time, LED resistor, PCB via current, and impedance calculators are planned. Check back soon or contact us to request a specific tool.
Need Professional PCB Design Services?
These calculators are the starting point. For complete PCB layout, impedance-controlled stackups, DFM review, and production-ready Gerber files — our senior engineers handle the full design lifecycle using Altium Designer and Cadence Allegro.
