Electricity calculator group

Alternating Current Calculators

Analyze sinusoidal voltage, impedance, phase, resonance, and alternating-current power.

Choose RMS, peak, phase, or impedance deliberately

Alternating-current calculations depend on waveform convention. Confirm whether a source gives RMS, peak, or peak-to-peak voltage and whether three-phase values are line or phase quantities.

Frequency affects reactance, impedance, resonance, and phase. Use one frequency throughout a case, and keep nonsinusoidal waveforms separate from formulas that assume a sine wave.

Alternating Current calculators by result

Frequency PeriodConvert frequency into cycle period.Angular FrequencyConvert hertz into angular frequency.Peak RMS VoltageConvert sinusoidal peak voltage to RMS.Peak-to-Peak VoltageConvert peak-to-peak amplitude.Phase Shift TimeConvert a time offset into phase angle.Inductive ReactanceCalculate inductive reactance and ideal RMS current at a selected voltage.Capacitive ReactanceCalculate capacitive reactance and ideal RMS current at a selected voltage.Series RL ImpedanceFind series resistance-inductance impedance magnitude.Series RC ImpedanceFind series resistance-capacitance impedance magnitude.Series RLC ImpedanceCalculate series RLC impedance.Parallel RLC ImpedanceCalculate ideal parallel RLC impedance.Resonant FrequencyFind ideal LC resonance.Resonance BandwidthEstimate half-power bandwidth from quality factor.Real Reactive Apparent PowerCalculate real power from RMS voltage, RMS current, and power factor.Single-Phase PowerCalculate single-phase real power.Line Phase VoltageConvert line voltage to phase voltage.Power FactorCalculate power factor from real and apparent power.Power Factor CorrectionSize a three-phase correction bank from power, power factors, frequency, and voltage.Total Harmonic DistortionCalculate THD from combined harmonic RMS.Three-Phase PowerCalculate balanced three-phase power.

Reactance and impedance workflow

Begin with inductive or capacitive reactance when a single reactive element is involved. Use the RL, RC, or RLC pages when resistance and reactance must be combined into impedance magnitude.

Resonant frequency locates the ideal LC balance; resonance bandwidth adds quality factor. Real components also introduce resistance, parasitics, and frequency-dependent loss.

Power and waveform calculations

Single-phase and three-phase power require RMS voltage, current, and power factor on a compatible basis. Real, reactive, and apparent power describe different parts of the same AC load.

Power-factor correction should use measured real power, starting power factor, target power factor, frequency, line voltage, and the intended capacitor connection. Harmonic resonance must be reviewed separately.

Before using an AC result

Record phase arrangement, frequency, waveform distortion, and meter bandwidth. A true-RMS reading and an average-responding meter can disagree on nonlinear loads.

Check insulation, current, thermal, and transient ratings in addition to the calculated steady-state value.

Instrument bandwidth and phase reference

Confirm that meters, probes, and current transformers have adequate bandwidth for the waveform being measured. A device can report a stable number while missing harmonic or transient content that matters to heating or peak stress.

Keep the phase reference and sign convention with reactive-power and phase-shift results. Mixing leading and lagging conventions can reverse the meaning of a correction or comparison.