diff --git a/specparam/tests/utils/test_data.py b/specparam/tests/utils/test_data.py
index 860d7f5a..c23d5651 100644
--- a/specparam/tests/utils/test_data.py
+++ b/specparam/tests/utils/test_data.py
@@ -9,6 +9,13 @@
 ###################################################################################################
 ###################################################################################################
 
+def test_get_freq_ind():
+
+    freqs = np.array([1, 2, 3, 4, 5])
+
+    assert get_freq_ind(freqs, 2.2) == 1
+    assert get_freq_ind(freqs, 3.7) == 3
+
 def test_compute_average():
 
     data = np.array([[0., 1., 2., 3., 4., 5.],
diff --git a/specparam/utils/data.py b/specparam/utils/data.py
index 097780ec..6661c473 100644
--- a/specparam/utils/data.py
+++ b/specparam/utils/data.py
@@ -30,6 +30,25 @@
 ###################################################################################################
 ###################################################################################################
 
+def get_freq_ind(freqs, freq):
+    """Get the index of the  closest frequency value to a specified input frequency.
+
+    Parameters
+    ----------
+    freqs : 1d array
+        Frequency values.
+    freq : float
+        Frequency value to select closest index to.
+
+    Returns
+    -------
+    int
+        Index of closest value in `freqs` to `freq`.
+    """
+
+    return np.argmin(np.abs(freqs - freq))
+
+
 def compute_average(data, average='mean'):
     """Compute the average across an array of data.