Calculator Form
Choose a mode. Fill the required values only.
Example Data Table
| Case | Input Basis | Known Values | Duty Cycle | Frequency | Average Voltage |
|---|---|---|---|---|---|
| Example 1 | High Time + Low Time | 2 ms on, 8 ms off, 12 V | 20% | 100 Hz | 2.4 V |
| Example 2 | High Time + Period | 0.5 ms on, 2 ms period, 5 V | 25% | 500 Hz | 1.25 V |
| Example 3 | Duty Cycle + Frequency | 60%, 1000 Hz, 24 V | 60% | 1000 Hz | 14.4 V |
Formula Used
| Duty Cycle | Duty (%) = (High Time / Period) × 100 |
| Period | Period = High Time + Low Time |
| Frequency | Frequency = 1 / Period |
| High Time from Duty | High Time = Duty(decimal) × Period |
| Low Time | Low Time = Period - High Time |
| Average Voltage | Average Voltage = Supply Voltage × Duty(decimal) |
| RMS Voltage | RMS Voltage = Supply Voltage × √Duty(decimal) |
| Average Current | Average Current = Peak Current × Duty(decimal) |
| RMS Current | RMS Current = Peak Current × √Duty(decimal) |
How to Use This Calculator
- Select the calculation mode that matches your known data.
- Choose the time unit for timing inputs.
- Enter the required values for the selected mode.
- Add supply voltage or peak current if you want electrical outputs.
- Press Calculate to show the result above the form.
- Download the result as CSV or PDF if needed.
PWM Duty Calculator Guide
Pulse width modulation is a common control method in engineering. It changes average power without changing the input supply level. The signal switches between low and high states. Duty cycle tells you how long the signal stays high in one full period.
A PWM duty calculator helps you move between timing values quickly. You can start with high time and period. You can also use high time and low time. Some designs begin with duty cycle and frequency. This page supports all of those common cases.
Why duty cycle matters
Duty cycle affects average voltage, current, and delivered power. A higher duty cycle means the signal stays high longer. That usually increases the average output. Engineers use this relation in motor drives, LED dimming, switching converters, and embedded control systems.
Important PWM terms
High time is the on-time of the signal. Low time is the off-time. Period is one complete switching cycle. Frequency is the number of cycles per second. Mark-space ratio compares on-time to off-time. These values describe waveform behavior clearly.
Electrical outputs from duty cycle
If you know the supply voltage, you can estimate average voltage and RMS voltage. If you know the peak current, you can estimate average current and RMS current. These outputs help with thermal checks, filter design, and load planning.
Where engineers use PWM calculations
PWM appears in microcontrollers, inverters, buck converters, fan control, audio shaping, and battery systems. It is also used in industrial automation and robotics. Fast and accurate duty cycle calculations reduce design mistakes and improve signal tuning.
Using this tool effectively
Choose the input mode that matches your data. Enter values in one time unit. Keep units consistent. Add optional electrical values when you need deeper analysis. The calculator then returns timing results and practical output estimates for fast engineering decisions.
FAQs
1. What is PWM duty cycle?
PWM duty cycle is the percentage of one period where the signal remains high. It shows how long the pulse is on compared with the full switching cycle.
2. How do I calculate duty cycle from on-time and period?
Divide the high time by the full period. Then multiply the result by 100. That gives the duty cycle percentage for the waveform.
3. Can this calculator find frequency too?
Yes. When the period is known or derived, the calculator computes frequency using the relation frequency equals one divided by period.
4. Why is average voltage lower than supply voltage?
Average voltage depends on duty cycle. The signal is not high all the time. A lower duty cycle reduces the average value seen by the load.
5. What is the difference between average and RMS voltage?
Average voltage shows the mean value over time. RMS voltage reflects equivalent heating effect. Both are useful, but they describe different electrical behaviors.
6. Can I use milliseconds or microseconds?
Yes. Select the time unit first. Then enter all timing values in that same unit. The calculator converts them internally for correct results.
7. What happens at 0% or 100% duty cycle?
At 0%, the signal stays low for the full period. At 100%, it stays high for the full period. Off-time or on-time becomes zero.
8. Where is PWM duty cycle used in practice?
PWM duty cycle is widely used in motor speed control, LED dimming, power converters, embedded systems, fan control, robotics, and automation circuits.