Peak to Peak Voltage Calculator
Enter any one of Vpp, Vpeak, or Vrms and get the full waveform picture: peak-to-peak, peak, RMS, and average rectified voltage for sine, square, and triangle waves, with an optional DC offset.
Waveform Voltage Calculator
Waveform Preview
Frequency / Period
Frequency and period describe the same signal: f = 1 ÷ T. Edit either field.
Conversion Factors
| Waveform | Vpeak from Vpp | Vrms from Vpp | Vavg from Vpp | Crest factor |
|---|---|---|---|---|
| Sine | × 0.5 | ÷ 2.828427 | ÷ 3.141593 | 1.414214 |
| Square | × 0.5 | ÷ 2.000000 | × 0.5 | 1.000000 |
| Triangle | × 0.5 | ÷ 3.464102 | ÷ 4.000000 | 1.732051 |
Exact forms: sine Vrms = Vpp ÷ (2√2), Vavg = Vpp ÷ π; square Vrms = Vpp ÷ 2, Vavg = Vpp ÷ 2; triangle Vrms = Vpp ÷ (2√3), Vavg = Vpp ÷ 4. Crest factor = Vpeak ÷ Vrms = √2, 1, √3.
Worked Examples
1. 10 Vpp sine wave
- Vpeak = Vpp ÷ 2 = 10 ÷ 2 = 5 V
- Vrms = Vpp ÷ 2.828427 = 10 ÷ 2.828427 = 3.53553 V
- Vavg = 2 × Vpeak ÷ π = 10 ÷ π = 3.18310 V
2. 5 Vrms sine wave to peak-to-peak
- Vpp = Vrms × 2√2 = 5 × 2.828427 = 14.1421 V
- Vpeak = Vpp ÷ 2 = 14.1421 ÷ 2 = 7.07107 V
3. 12 Vpp square wave
- Vpeak = 12 ÷ 2 = 6 V
- Vrms = Vpp ÷ 2 = 6 V (square wave: RMS equals peak)
- Crest factor = 6 ÷ 6 = 1.000
4. 6 Vpp triangle wave
- Vpeak = 6 ÷ 2 = 3 V
- Vrms = Vpp ÷ (2√3) = 6 ÷ 3.464102 = 1.73205 V
- Vavg = Vpp ÷ 4 = 1.5 V
5. Frequency 1 kHz to period
- T = 1 ÷ f = 1 ÷ 1000 = 0.001 s = 1 ms
- Check: 50 Hz gives T = 1 ÷ 50 = 0.02 s = 20 ms
6. 10 Vpp sine wave with 3 V DC offset
- Vpp is unchanged by the offset: 10 V
- Vpeak+ = 3 + 5 = 8 V, Vpeak− = 3 − 5 = −2 V
- Total Vrms = √(3² + 3.53553²) = √21.5 = 4.63681 V
How It Is Calculated
All conversions go through the AC peak voltage Vpeak. From Vpp: Vpeak = Vpp ÷ 2. From Vrms: Vpeak = Vrms × √2 (sine), Vrms × 1 (square), Vrms × √3 (triangle). Then Vrms = Vpeak ÷ √2 (sine), Vpeak (square), Vpeak ÷ √3 (triangle). Average rectified voltage: 2 × Vpeak ÷ π (sine), Vpeak (square), Vpeak ÷ 2 (triangle). A DC offset shifts both peaks by Vdc and makes the total RMS √(Vdc² + Vrms_ac²); with a nonzero offset the rectified average is evaluated numerically over one cycle. Frequency and period follow f = 1 ÷ T. Display rounds to 6 significant digits.
Frequently Asked Questions
What is peak-to-peak voltage (Vpp)?
Peak-to-peak voltage (Vpp) is the difference between the highest and lowest voltage of a waveform over one full cycle. For a waveform centered at zero, Vpp equals twice the peak voltage (Vpp = 2 × Vpeak).
What is the difference between Vpp, Vpeak, and Vrms?
Vpp measures the full swing from the lowest to the highest point of a waveform. Vpeak is the maximum from zero. Vrms is the DC-equivalent voltage that would deliver the same average power into a resistor. Vpp and Vpeak describe size; Vrms describes heating power.
How do you convert peak-to-peak voltage to RMS?
The conversion depends on the waveform shape. For a sine wave, Vrms = Vpp ÷ 2.828, that is Vpp ÷ (2√2). For a square wave, Vrms = Vpp ÷ 2. For a triangle wave, Vrms = Vpp ÷ 3.464, that is Vpp ÷ (2√3).
Is Vrms always Vpp divided by 2.828?
No. The factor 2.828 (2√2) applies to sine waves only. A 12 Vpp square wave has Vrms = 12 ÷ 2 = 6 V, but the sine formula would give 12 ÷ 2.828 = 4.243 V, under-reading the true RMS by about 29%. Always match the factor to the waveform.
What is the RMS voltage of a square wave?
For a symmetric square wave, Vrms equals the peak voltage: Vrms = Vpeak = Vpp ÷ 2. The waveform spends all of its time at the positive or negative extreme, so the average of the squared voltage is simply the peak value squared.
What is the RMS voltage of a triangle wave?
Vrms = Vpeak ÷ √3 = Vpp ÷ (2√3), which is approximately Vpp ÷ 3.464. For example, a 6 Vpp triangle wave has Vrms = 6 ÷ 3.464 = 1.732 V.
Why is RMS voltage called effective voltage?
RMS stands for root mean square, and it is defined so that an AC voltage and a DC voltage with the same RMS value deliver identical average power into a resistive load. 120 V RMS AC heats a resistor exactly like 120 V DC.
What is crest factor and why does it matter?
Crest factor is the ratio Vpeak ÷ Vrms. It equals √2 ≈ 1.414 for a sine wave, 1.000 for a square wave, and √3 ≈ 1.732 for a triangle wave. A high crest factor means large instantaneous peaks relative to the heating power, which matters when choosing component voltage ratings.
Does frequency change Vpp or Vrms?
No. Vpp, Vpeak, Vrms, and the average depend only on amplitude and waveform shape, not on frequency. Frequency and period are linked by f = 1 ÷ T: a 1 kHz signal has a period of 1 ms, and a 50 Hz signal has a period of 20 ms.
What is average rectified voltage?
It is the average of the absolute value of the waveform over one cycle, the DC level a full-wave rectifier would produce before any filtering. For a sine wave, Vavg = 2 × Vpeak ÷ π ≈ 0.6366 × Vpeak. For a symmetric square wave it equals Vpeak, and for a triangle wave it equals Vpeak ÷ 2.
How does a DC offset change Vpp and Vrms?
A DC offset does not change Vpp, because Vpp only measures the swing between the two extremes. Both peaks shift by the offset: Vpeak+ = Vdc + Vpeak and Vpeak− = Vdc − Vpeak. The total RMS becomes √(Vdc² + Vrms_ac²). Example: a 10 Vpp sine wave (3.5355 V RMS) with a 3 V offset has total RMS √(9 + 12.5) = 4.63681 V.
How do I measure Vpp with an oscilloscope?
Set the coupling to DC and measure from the lowest point of the trace to the highest point; that is Vpp. Divide by 2 for Vpeak, then apply the waveform factor: divide by √2 for a sine wave, by 1 for a square wave, or by √3 for a triangle wave to get Vrms.
My multimeter reads Vrms. How do I get Vpp?
Multiply the reading by twice the crest factor of the waveform. For a sine wave: Vpp = Vrms × 2√2 ≈ Vrms × 2.828. A meter reading of 5 V RMS on a sine wave means 5 × 2.828 = 14.142 V peak-to-peak.
What is 120 V and 230 V mains in peak-to-peak?
Mains voltages are specified as RMS sine waves. 120 V RMS = 339.41 V peak-to-peak (169.71 V peak). 230 V RMS = 650.54 V peak-to-peak (325.27 V peak).
How is this different from the voltage-converter tool?
The voltage-converter tool converts voltage units such as V, mV, and kV, solves voltage dividers and Ohm's law, and computes wire voltage drop: circuit math. This calculator does waveform math: Vpp, Vpeak, Vrms, average rectified voltage, and DC offset for sine, square, and triangle waveforms. They are complementary tools for different jobs.
What formulas does this calculator use?
Sine: Vpeak = Vpp ÷ 2, Vrms = Vpp ÷ (2√2), Vavg = 2 × Vpeak ÷ π. Square: Vrms = Vpp ÷ 2, Vavg = Vpeak. Triangle: Vrms = Vpp ÷ (2√3), Vavg = Vpeak ÷ 2. With a DC offset, Vpp is unchanged, Vpeak+ = Vdc + Vpeak, Vpeak− = Vdc − Vpeak, and total Vrms = √(Vdc² + Vrms_ac²). Frequency and period follow f = 1 ÷ T.
Free tool by NRTechStudio