diff --git a/packages/block-library/src/gallery/style.scss b/packages/block-library/src/gallery/style.scss
index 26053298a3b3b..a62465bb4f225 100644
--- a/packages/block-library/src/gallery/style.scss
+++ b/packages/block-library/src/gallery/style.scss
@@ -101,6 +101,13 @@
 			&.columns-#{ $i } .blocks-gallery-item {
 				width: calc((100% - #{ $grid-size-large } * #{ $i - 1 }) / #{ $i });
 				margin-right: 16px;
+
+				// Rules inside this query are only run by Microsoft Edge.
+				// Edge miscalculates `calc`, so we have to add some buffer.
+				// See also https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/15637241/
+				@supports (-ms-ime-align:auto) {
+					width: calc((100% - #{ $grid-size-large } * #{ $i - 1 }) / #{ $i } - 1px);
+				}
 			}
 		}