diff --git a/wpimath/src/main/java/edu/wpi/first/wpilibj/LinearFilter.java b/wpimath/src/main/java/edu/wpi/first/wpilibj/LinearFilter.java
index 5d0e649e59..1f782d5281 100644
--- a/wpimath/src/main/java/edu/wpi/first/wpilibj/LinearFilter.java
+++ b/wpimath/src/main/java/edu/wpi/first/wpilibj/LinearFilter.java
@@ -74,6 +74,9 @@ public class LinearFilter {
    * Creates a one-pole IIR low-pass filter of the form: y[n] = (1-gain)*x[n] + gain*y[n-1] where
    * gain = e^(-dt / T), T is the time constant in seconds.
    *
+   * <p>Note: T = 1 / (2 pi f) where f is the cutoff frequency in Hz, the frequency above which the
+   * input starts to attenuate.
+   *
    * <p>This filter is stable for time constants greater than zero.
    *
    * @param timeConstant The discrete-time time constant in seconds.
@@ -91,6 +94,9 @@ public class LinearFilter {
    * Creates a first-order high-pass filter of the form: y[n] = gain*x[n] + (-gain)*x[n-1] +
    * gain*y[n-1] where gain = e^(-dt / T), T is the time constant in seconds.
    *
+   * <p>Note: T = 1 / (2 pi f) where f is the cutoff frequency in Hz, the frequency below which the
+   * input starts to attenuate.
+   *
    * <p>This filter is stable for time constants greater than zero.
    *
    * @param timeConstant The discrete-time time constant in seconds.
diff --git a/wpimath/src/main/native/include/frc/LinearFilter.h b/wpimath/src/main/native/include/frc/LinearFilter.h
index 3faec05f8f..449fadf196 100644
--- a/wpimath/src/main/native/include/frc/LinearFilter.h
+++ b/wpimath/src/main/native/include/frc/LinearFilter.h
@@ -104,6 +104,9 @@ class LinearFilter {
    *   y[n] = (1 - gain) * x[n] + gain * y[n-1]<br>
    * where gain = e<sup>-dt / T</sup>, T is the time constant in seconds
    *
+   * Note: T = 1 / (2 pi f) where f is the cutoff frequency in Hz, the frequency
+   * above which the input starts to attenuate.
+   *
    * This filter is stable for time constants greater than zero.
    *
    * @param timeConstant The discrete-time time constant in seconds.
@@ -121,6 +124,9 @@ class LinearFilter {
    *   y[n] = gain * x[n] + (-gain) * x[n-1] + gain * y[n-1]<br>
    * where gain = e<sup>-dt / T</sup>, T is the time constant in seconds
    *
+   * Note: T = 1 / (2 pi f) where f is the cutoff frequency in Hz, the frequency
+   * below which the input starts to attenuate.
+   *
    * This filter is stable for time constants greater than zero.
    *
    * @param timeConstant The discrete-time time constant in seconds.