When to use this calculator
Find the minus-three-decibel cutoff of an ideal RC low-pass filter. Unloaded first-order RC low-pass model with ideal components.
Explore the ac power & reactance calculators for other questions in this topic. For a related calculation, use the Reactive Power Calculator: Find reactive-power magnitude from compatible apparent and real power.
PUTTING IT INTO PRACTICE
RC Low Pass Cutoff: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Resistance (Ω) | 1,000 |
| Capacitance (μF) | 1 |
| Result | 159.154943 Hz |
- Check the input labels and enter the example values above.
- Apply the relationship: Cutoff frequency = 1/(2πRC).
- The result is 159.154943 Hz, rounded for display.
How to interpret your result
Unloaded first-order RC low-pass model with ideal components.
Use RMS values in the AC power relationships. Apparent power is measured in VA and real power in watts. Pure-sine conversions and balanced three-phase equations only apply under their stated assumptions.
Frequently asked questions
Why can volt-amps differ from watts?
Apparent power is the RMS voltage-current product, while real power also reflects power factor. They are numerically equal only at a power factor of one.
When is the rc low pass cutoff calculator useful?
Find the minus-three-decibel cutoff of an ideal RC low-pass filter. Unloaded first-order RC low-pass model with ideal components.
How do I use the rc low pass cutoff calculator?
Enter resistance (ω), capacitance (μf). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Cutoff frequency = 1/(2πRC).
What should I check before using the result?
Unloaded first-order RC low-pass model with ideal components.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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