Enter an ohms value and frequency into the calculator to determine the capacitance. This assumes the ohms value represents the magnitude of capacitive reactance, |XC|, at that frequency (or, equivalently, the resistance R of a 1st‑order RC circuit evaluated at its cutoff frequency where |XC| = R). This calculator can also evaluate any of the variables given the others are known.
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Ohms To Farads Formula
The following formula is used to calculate the capacitance in Farads (F) for a given frequency when the ohms value represents the magnitude of capacitive reactance, |XC| (in Ω). The same relationship also applies at the cutoff frequency of a first‑order RC circuit, where |XC| = R.
C = 1 / (2 * π * f * R)
Variables:
- C is the capacitance in Farads (F)
- R is an ohms value (Ω): either the capacitor’s reactance magnitude |XC| at frequency f, or the resistor value at an RC cutoff frequency where |XC| = R
- f is the frequency in Hertz (Hz)
- π is a constant, approximately equal to 3.14159
To calculate the capacitance, multiply the ohms value by the frequency, then multiply the result by 2 and π. Finally, take the reciprocal of the result to get the capacitance in Farads.
| Ohms value (Ω) | Capacitance (nF) |
|---|---|
| 10 | 15915.494 |
| 22 | 7234.316 |
| 47 | 3386.340 |
| 100 | 1591.549 |
| 220 | 723.432 |
| 470 | 338.638 |
| 1000 | 159.155 |
| 2200 | 72.378 |
| 3300 | 48.230 |
| 4700 | 33.864 |
| 10000 | 15.915 |
| 22000 | 7.234 |
| 33000 | 4.823 |
| 47000 | 3.387 |
| 68000 | 2.342 |
| 100000 | 1.592 |
| 220000 | 0.723 |
| 470000 | 0.339 |
| 1000000 | 0.159 |
| 2200000 | 0.072 |
| * Rounded to 3 decimals. Assumes frequency f = 1.00 kHz and that the ohms value represents |XC| (capacitive reactance magnitude) (or a resistor value at an RC cutoff frequency where |XC| = R). Formula: C = 1 / (2π f R). 1 nF = 1×10⁻⁹ F. | |
What is Ohms To Farads?
Ohms and Farads are units used in electrical circuits, but they measure different things and cannot be directly converted without additional context. Ohms (Ω) can describe resistance, but they can also describe a reactance/impedance magnitude such as capacitive reactance |XC|. Farads (F) measure capacitance, which is the ability of a system to store electric charge. In practice, “Ohms to Farads” usually means finding the capacitance that produces a desired capacitive reactance (in Ω) at a specified frequency (or finding the capacitance for an RC circuit’s cutoff frequency, where |XC| = R).
How to Calculate Ohms To Farads?
The following steps outline how to calculate the Ohms To Farads using the formula: C = 1 / (2 * π * f * R), where R is the target ohms value (often |XC|, or a resistor value at cutoff).
- First, determine the target ohms value (R) in Ohms (Ω) (typically |XC|, or a resistor value at cutoff).
- Next, determine the frequency in Hertz (f).
- Next, gather the formula from above: C = 1 / (2 * π * f * R).
- Finally, calculate the capacitance in Farads (C).
- After inserting the variables and calculating the result, check your answer with a calculator.
Example Problem:
Use the following variables as an example problem to test your knowledge:
Ohms value (R) in Ohms (Ω) = 100
Frequency (f) in Hertz (Hz) = 50
π (constant) = 3.14159
