1st Order Passive Filter Calculator

Select Oscillator:

RC Low Pass Filter RL Low Pass Filter RC High Pass Filter RL High Pass Filter

RC LPF Calculator

Calculate Frequency(f_c):
R: Ω KΩ MΩ
C: µF nF pF

Results:
f_c:
φ= 45° and X_c=R at cutoff frequency fc

Calculate R(=X_c):

f_c: Hz KHz MHz
C: µF nF pF

Results:
R:

Calculate C:

f_c: Hz KHz MHz
R: Ω KΩ MΩ

Results:
C:

Calculate φ:

φ:
f_c: Hz KHz MHz
C: µF nF pF

Results:
R:

Calculate E & τ:

V: V
R: Ω KΩ MΩ
C: µF nF pF

Results:
E: Energy stored in C
Time Constants:
\(\tau\): 63.2% of its final value
\(\tau\): within 0.01% of its final value

Formula:
Cutoff frequency:
\(f_0=\frac{1}{2 \pi R C}\)
Capactive Reactance:
\(X_C=\frac{1}{2 \pi f_0 C}\)

RL LPF Calculator

Calculate Frequency(f_c):
R(=X_L): Ω KΩ MΩ
L: mH µH nH

Results:
f_c:

Calculate R(=X_L):

f_c: Hz KHz MHz
L: mH µH nH

Results:
R(=X_L):

Calculate L:

f_c: Hz KHz MHz
R(=X_L): Ω KΩ MΩ

Results:
L:

Formula:
Cutoff frequency:
\(f_0=\frac{R}{2 \pi L}\)
Inductive Reactance:
\(X_L=2 \pi f_0 L\)

RC HPF Calculator

Calculate Frequency(f_c):
R(=X_C): Ω KΩ MΩ
C: µF nF pF

Results:
f_c:

Calculate R(=X_C):

f_c: Hz KHz MHz
C: µF nF pF

Results:
R(=X_C):

Calculate C:

f_c: Hz KHz MHz
R(=X_C): Ω KΩ MΩ

Results:
C:

Formula:
Cutoff frequency:
\(f_0=\frac{1}{2 \pi R C}\)
Capactive Reactance:
\(X_C=\frac{1}{2 \pi f_0 C}\)

RL HPF Calculator

Calculate Frequency(f_c):
R(=X_L): Ω KΩ MΩ
L: mH µH nH

Results:
f₀:

Calculate R(=X_L):

f_c: Hz KHz MHz
L: mH µH nH

Results:
R(=X_L):

Calculate L:

f_c: Hz KHz MHz
R(=X_L): Ω KΩ MΩ

Results:
L:

Formula:
Cutoff frequency:
\(f_0=\frac{R}{2 \pi L}\)
Inductive Reactance:
\(X_L=2 \pi f_0 L\)