diff --git a/docs/source_docs/user_guide/inputs/output/monitors.rst b/docs/source_docs/user_guide/inputs/output/monitors.rst
index 5ff9dd7519d6f6f8173ce7804b1a7b59267ff9d3..10181c93520809e669574dd718b645c1dc253026 100644
--- a/docs/source_docs/user_guide/inputs/output/monitors.rst
+++ b/docs/source_docs/user_guide/inputs/output/monitors.rst
@@ -406,16 +406,37 @@ Volume Integral
 
    .. math:: \int \phi dV = \sum_{ijk}{\phi_{ijk} \lvert V_{ijk}} \rvert
 
+Volume-Weighted Integral
+   +--------------------------------------------------+
+   | Eulerian::VolumeIntegral::VolumeWeightedIntegral |
+   +--------------------------------------------------+
+
+   The volume-weighted integral is computed by summing the product of the
+   selected field variable, phase volume fraction and cell volume.
+
+   .. math:: \int\varepsilon \phi dV = \sum_{ijk}{\phi_{ijk} \varepsilon_{ijk} \lvert V_{ijk}} \rvert
+
+Volume Average
+   +-----------------------------------------+
+   | Eulerian::VolumeIntegral::VolumeAverage |
+   +-----------------------------------------+
+
+   The volume-weighted average is computed by dividing the summation of the
+   product of the selected field variable and cell volume by the sum of the cell
+   volumes.
+
+    .. math:: \frac{\int\phi dV}{V} = \frac{\sum_{ijk}{\phi_{ijk} \lvert V_{ijk} \rvert}}{\sum_{ijk}{\lvert V_{ijk} \rvert}}
+
 Volume-Weighted Average
    +-------------------------------------------------+
    | Eulerian::VolumeIntegral::VolumeWeightedAverage |
    +-------------------------------------------------+
 
    The volume-weighted average is computed by dividing the summation of the
-   product of the selected field variable and cell volume by the sum of the cell
-   volumes.
+   product of the selected field variable, phase volume fraction and cell volume
+   by the sum of the product of the phase volume fraction and cell volumes.
 
-    .. math:: \frac{\int\phi dV}{V} = \frac{\sum_{ijk}{\phi_{ijk} \lvert V_{ijk} \rvert}}{\sum_{ijk}{\lvert V_{ijk} \rvert}}
+    .. math:: \frac{\int\varepsilon\phi dV}{\int\varepsilon dV} = \frac{\sum_{ijk}{\phi_{ijk} \varepsilon_{ijk} \lvert V_{ijk} \rvert}}{\sum_{ijk}{\varepsilon_{ijk} \lvert V_{ijk} \rvert}}
 
 Mass-Weighted Integral
    +------------------------------------------------+