Calculators & Tools
Free in-browser tools for DIY electronics — power, voltage, current, heatsink, and component-sizing calculators. All math happens in your browser; nothing is sent to any server.
- AC Dimmer Power Calculator Calculate actual RMS voltage, real power, and current through a TRIAC phase-cut AC dimmer at any dimming level. Live waveform visualization.
- TRIAC Heatsink Sizing Calculator Find the right heatsink for BTA16, BTA24, BT136, BT139 TRIACs. Calculates power dissipation, required thermal resistance, junction temperature, with go/no-go verdict.
- LED Resistor Calculator Pick the right current-limiting resistor for any LED — single, series, or multiple LEDs. Color presets (red, blue, green, white, IR, UV), closest E24 standard value, recommended wattage, and a live circuit diagram.
- Voltage Divider Calculator Forward mode: compute Vout, current, and power from R1/R2. Reverse mode: find E24-standard R1/R2 pairs to step any voltage down to a target (e.g. 12V battery → 5V Arduino ADC). With circuit diagram.
- Resistor Color Code Calculator Two-way 3/4/5/6-band decoder and encoder. Pick colors → get value, or type a value → see which bands to look for. Live visual rendering on a resistor, plus a reference table and 9 common values to memorize.
More tools coming: LED resistor calculator, voltage divider, PWM duty cycle ↔ DC voltage, MOSFET gate-drive checker, resistor color-code reader. Got a request? Open an issue on GitHub.