diff --git a/engine/userguide/storagedriver/imagesandcontainers.md b/engine/userguide/storagedriver/imagesandcontainers.md
index bf363b0098..a02d5f987a 100644
--- a/engine/userguide/storagedriver/imagesandcontainers.md
+++ b/engine/userguide/storagedriver/imagesandcontainers.md
@@ -81,7 +81,8 @@ command. Two different columns relate to size.
   each container
 
 - `virtual size`: the amount of data used for the read-only image data
-  used by the container. Multiple containers may share some or all read-only
+  used by the container plus the container's writable layer `size`. 
+  Multiple containers may share some or all read-only
   image data. Two containers started from the same image share 100% of the
   read-only data, while two containers with different images which have layers
   in common share those common layers. Therefore, you can't just total the
@@ -90,8 +91,9 @@ command. Two different columns relate to size.
 
 The total disk space used by all of the running containers on disk is some
 combination of each container's `size` and the `virtual size` values. If
-multiple containers have exactly the same `virtual size`, they are likely
-started from the same exact image.
+multiple containers started from the same exact image, the total size on disk for 
+these containers would be SUM (`size` of containers) plus one container's 
+(`virtual size`- `size`).
 
 This also does not count the following additional ways a container can take up
 disk space: