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RMS and Average Value Calculator

Calculate RMS (Root Mean Square) and average values of AC and periodic waveforms including sine, square, triangular, and custom signals. Ideal for electrical engineering, power electronics, signal processing, and circuit analysis.

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unit
type
Hz
sec
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unit
Please enter all required values.
RESULTS
Vrms
Vavg

Input Parameters Specification

Peak Value VpkMaximum waveform amplitude used to calculate RMS value and average value.
Waveform TypeSelect sine, rectified sine, square, sawtooth, trapezoidal, or DC offset waveform.
Frequency and DurationUsed for pulse-based half sine, square wave, sawtooth wave, and trapezoidal waveform RMS calculations.
Base and DC OffsetBase B is used for trapezoidal waves, while Vdc is used for sine wave with DC offset.

Practical Operational Examples

Sine Wave RMS

For a sine wave, enter only Vpk and select Sine wave to calculate Vrms = Vpk / sqrt(2).

Pulse Wave Analysis

For square, sawtooth, half sine, or trapezoidal waveforms, enter frequency and duration to calculate RMS and average values.

Rectifier Output

Use full rectified or half rectified options when checking charger, rectifier, inverter and AC-to-DC waveform values.

DC Offset Signal

Use sine wave with DC offset when a waveform rides above or below zero reference level.

Diagrams & Theory

This RMS and average calculator supports common electrical waveforms used in AC analysis, rectifier circuits, pulsed power, waveform measurement and signal processing.

Avg RMS T

Formulas & Mathematical Logic

Sine wave: Vrms = Vpk / sqrt(2), Vavg = 0.
Full rectified wave: Vrms = Vpk / sqrt(2), Vavg = 0.637 × Vpk.
Half rectified sine wave: Vrms = Vpk / 2, Vavg = 0.318 × Vpk.
Sine wave with DC offset: Vrms = sqrt(Vdc² + Vpk² / 2), Vavg = Vdc.
Half sine pulse: Vrms = Vpk × sqrt(F × T / 2), Vavg = 2 × F × T × Vpk / PI.
Square pulse: Vrms = Vpk × sqrt(F × T), Vavg = F × T × Vpk.
Sawtooth pulse: Vrms = Vpk × sqrt(F × T / 3), Vavg = Vpk × F × T / 2.
Trapezoidal wave: Vrms = Vpk × sqrt(F × ((B - T) + 3 × T) / 3), Vavg = Vpk × F × (B + T) / 2.

Step-by-Step Example

Example 1: Sine wave with Vpk = 10 unit.
Vrms = 10 / sqrt(2) = 7.071.
Vavg = 0 for a normal AC sine wave over one full cycle.
Example 2: Square pulse with Vpk = 10, frequency = 100 Hz, duration = 0.002 sec.
Duty part = F × T = 100 × 0.002 = 0.2.
Vrms = 10 × sqrt(0.2) = 4.472, and Vavg = 10 × 0.2 = 2.

How to Use This Calculator

Enter the peak value Vpk of the waveform.
Select the waveform type from the dropdown.
For DC offset waveform, enter Vdc when the field appears.
For pulse waveforms, enter frequency and duration T when shown.
For trapezoidal waveform, enter frequency, duration T and base B.
Click Calculate to get Vrms and Vavg.

About This Calculator

Calculate RMS and average values for common electrical waveforms.

The CalcBoy RMS and Average Calculator finds RMS and average values for sine, rectified sine, square pulse, sawtooth pulse, trapezoidal waveform and sine wave with DC offset.

RMS value is important because it represents the effective heating value of a waveform. Average value is useful when checking rectifier outputs, pulse duty behavior, DC content and waveform balance. Two waveforms can have the same peak value but very different RMS and average values, so using only peak voltage can give a wrong idea of power, heat or measurement result.

This calculator is helpful for AC waveform analysis, oscilloscope measurement, rectifier design, inverter waveform checking, power electronics, pulse circuits, motor drive signals, signal processing and electronics education. The waveform selector changes which extra inputs are needed, so simple sine and rectified wave calculations stay clean while pulse waveforms allow frequency and duration entries.

Use this tool for quick engineering estimates. Real measurements may differ because of waveform distortion, noise, duty cycle error, meter bandwidth, sampling rate, DC offset drift and non-ideal signal shape.

Best UseRMS and average waveform value calculation.
Supported InputsPeak value, waveform type, frequency, duration, base and DC offset.
Helpful ForAC analysis, rectifiers, inverters, pulse circuits and oscilloscope checks.
Design ReminderRMS affects heating; average affects DC content.
Tip: For power calculations, RMS value is usually the important number. For rectifier and DC output analysis, average value is often equally important.

Frequently Asked Questions

What is RMS value?

RMS is the effective value of a waveform. It is commonly used to estimate heating effect and equivalent DC power.

What is average value?

Average value is the mean value of the waveform over the selected cycle or pulse interval.

What is RMS of a sine wave?

For a sine wave, RMS value equals peak value divided by sqrt(2).

Why does a full sine wave average show zero?

A full AC sine wave has equal positive and negative halves, so its average over one complete cycle is zero.

Can this calculator be used for current waveforms?

Yes, the same formulas can apply to current if the peak input is treated as peak current instead of voltage.

Why do pulse waveforms need frequency and duration?

Frequency and duration define duty timing, which changes RMS and average values for pulse-shaped waveforms.

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About this tool

RMS and Average Value Calculator is a free online calculator tool. Use it to get instant, accurate results for your electronics calculations.