Electronics basics calculator

Enter any two values. The missing value and power are calculated locally.

Main result -
Formula -

Educational helper only. Real circuits depend on component tolerances, heat, ratings, wiring, and safety margins.

See examples

Pick a resistor for an LED

Enter supply voltage, LED forward voltage, and target current to calculate a current-limiting resistor.

Build a voltage divider

Use Vin, R1, and R2 to estimate output voltage, divider current, and resistor power.

Check digital resolution

Calculate ADC LSB size or DAC output step from bit depth and voltage range.

About this helper

This electronics basics calculator groups common beginner circuit calculations into one browser-based helper. Use the picker to switch between Ohm's law, voltage drop, LED resistor sizing, resistor networks, voltage dividers, current dividers, resistor color codes, battery capacity, PWM timing, decibels, ADC resolution, and DAC resolution. All calculations run locally in the browser.

Does this simulate real circuits?

No. It uses ideal formulas for quick planning and learning. Real circuits also depend on tolerances, heat, wiring, ratings, losses, and safety margins.

Can I use it for LED resistor values?

Yes. Enter supply voltage, LED forward voltage, LED current, and number of LEDs in series to estimate the resistor and wattage.

Are my values uploaded?

No. The calculations run locally in your browser and are not sent to a server.