Index: src/wp-content/themes/twentynineteen/sass/blocks/_blocks.scss
===================================================================
--- src/wp-content/themes/twentynineteen/sass/blocks/_blocks.scss	(revision 44335)
+++ src/wp-content/themes/twentynineteen/sass/blocks/_blocks.scss	(working copy)
@@ -502,20 +502,40 @@
 
 	//! Image
 	.wp-block-image {
+		max-width: 100%;
 
 		img {
 			display: block;
 		}
 
-		&.alignleft,
-		&.alignright {
-			max-width: 100%;
+		.aligncenter {
+			
+			@include postContentMaxWidth();
+
+			@include media(tablet) {
+				margin: 0;
+				width: $size__site-tablet-content;
+
+				img {
+					margin: 0 auto;
+				}
+			}
+
+			@include media(desktop) {
+				width: $size__site-desktop-content;
+
+				img {
+					margin: 0 auto;
+				}
+			}
 		}
 
 		&.alignfull img {
 			width: 100vw;
+			max-width: calc( 100% + (2 * #{$size__spacing-unit}));
 
 			@include media(tablet) {
+				max-width: calc( 125% + 150px );
 				margin-left: auto;
 				margin-right: auto;
 			}
Index: src/wp-content/themes/twentynineteen/style-rtl.css
===================================================================
--- src/wp-content/themes/twentynineteen/style-rtl.css	(revision 44335)
+++ src/wp-content/themes/twentynineteen/style-rtl.css	(working copy)
@@ -3934,20 +3934,56 @@
   }
 }
 
+.entry .entry-content .wp-block-image {
+  max-width: 100%;
+}
+
 .entry .entry-content .wp-block-image img {
   display: block;
 }
 
-.entry .entry-content .wp-block-image.alignleft, .entry .entry-content .wp-block-image.alignright {
-  max-width: 100%;
+.entry .entry-content .wp-block-image .aligncenter {
+  margin: 0;
 }
 
+@media only screen and (min-width: 768px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    max-width: calc(8 * (100vw / 12) - 28px);
+  }
+}
+
+@media only screen and (min-width: 1168px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    max-width: calc(6 * (100vw / 12) - 28px);
+  }
+}
+
+@media only screen and (min-width: 768px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    width: calc(8 * (100vw / 12) - 28px);
+  }
+  .entry .entry-content .wp-block-image .aligncenter img {
+    margin: 0 auto;
+  }
+}
+
+@media only screen and (min-width: 1168px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    width: calc(6 * (100vw / 12) - 28px);
+  }
+  .entry .entry-content .wp-block-image .aligncenter img {
+    margin: 0 auto;
+  }
+}
+
 .entry .entry-content .wp-block-image.alignfull img {
   width: 100vw;
+  max-width: calc( 100% + (2 * 1rem));
 }
 
 @media only screen and (min-width: 768px) {
   .entry .entry-content .wp-block-image.alignfull img {
+    max-width: calc( 125% + 150px);
     margin-right: auto;
     margin-left: auto;
   }
Index: src/wp-content/themes/twentynineteen/style.css
===================================================================
--- src/wp-content/themes/twentynineteen/style.css	(revision 44335)
+++ src/wp-content/themes/twentynineteen/style.css	(working copy)
@@ -3946,20 +3946,53 @@
   }
 }
 
+.entry .entry-content .wp-block-image {
+  max-width: 100%;
+}
+
 .entry .entry-content .wp-block-image img {
   display: block;
 }
 
-.entry .entry-content .wp-block-image.alignleft, .entry .entry-content .wp-block-image.alignright {
-  max-width: 100%;
+@media only screen and (min-width: 768px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    max-width: calc(8 * (100vw / 12) - 28px);
+  }
 }
 
+@media only screen and (min-width: 1168px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    max-width: calc(6 * (100vw / 12) - 28px);
+  }
+}
+
+@media only screen and (min-width: 768px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    margin: 0;
+    width: calc(8 * (100vw / 12) - 28px);
+  }
+  .entry .entry-content .wp-block-image .aligncenter img {
+    margin: 0 auto;
+  }
+}
+
+@media only screen and (min-width: 1168px) {
+  .entry .entry-content .wp-block-image .aligncenter {
+    width: calc(6 * (100vw / 12) - 28px);
+  }
+  .entry .entry-content .wp-block-image .aligncenter img {
+    margin: 0 auto;
+  }
+}
+
 .entry .entry-content .wp-block-image.alignfull img {
   width: 100vw;
+  max-width: calc( 100% + (2 * 1rem));
 }
 
 @media only screen and (min-width: 768px) {
   .entry .entry-content .wp-block-image.alignfull img {
+    max-width: calc( 125% + 150px);
     margin-left: auto;
     margin-right: auto;
   }