Everything runs in your browser. Pick a calculator, enter a few values, and use the result immediately.
Ohm's LawVoltage DividerLED ResistorSeries / Parallel ResistorsRC FiltersRLC ResonanceOp-Amp GainPWM TimingBattery LifeUART Baud Rate
Ohm's Law Calculator
Solve the missing value from any two known quantities.
Voltage Divider
Estimate tap voltage, divider current, and resistor dissipation.
LED Resistor
Pick a current-limiting resistor and a rough power margin.
Series / Parallel Resistors
Compare both equivalent cases from a quick list of values.
RC Filter
Find the cutoff and time constant for a single-pole passive stage.
RLC Resonance
Estimate resonant frequency, reactance, Q, and bandwidth.
Op-Amp Gain
Switch between inverting and non-inverting closed-loop formulas.
PWM Frequency / Duty Cycle
Convert PWM settings into a period plus the on and off windows.
Battery Life
Estimate runtime from capacity, efficiency loss, and duty cycle.
UART Baud Rate
Estimate throughput and bit timing from clock and divider settings.