diff --git a/src/calibre/gui2/tweak_book/boss.py b/src/calibre/gui2/tweak_book/boss.py
index 3e22e41ba5..677adbae2f 100644
--- a/src/calibre/gui2/tweak_book/boss.py
+++ b/src/calibre/gui2/tweak_book/boss.py
@@ -48,6 +48,7 @@ from calibre.gui2.tweak_book.widgets import (
     InsertSemantics, BusyCursor, InsertTag, FilterCSS, AddCover)
 from calibre.utils.config import JSONConfig
 from calibre.utils.icu import numeric_sort_key
+from calibre.utils.imghdr import identify
 
 _diff_dialogs = []
 last_used_transform_rules = []
@@ -861,7 +862,8 @@ class Boss(QObject):
                         self.refresh_file_list()
                         chosen_name = chosen_image_is_external[0]
                     href = current_container().name_to_href(chosen_name, edname)
-                    ed.insert_image(href, fullpage=fullpage, preserve_aspect_ratio=preserve_ar)
+                    fmt, width, height = identify(current_container().raw_data(chosen_name, decode=False))
+                    ed.insert_image(href, fullpage=fullpage, preserve_aspect_ratio=preserve_ar, width=width, height=height)
             elif action[0] == 'insert_hyperlink':
                 self.commit_all_editors_to_container()
                 d = InsertLink(current_container(), edname, initial_text=ed.get_smart_selection(), parent=self.gui)
diff --git a/src/calibre/gui2/tweak_book/editor/text.py b/src/calibre/gui2/tweak_book/editor/text.py
index 479bed211a..e76c0b34b0 100644
--- a/src/calibre/gui2/tweak_book/editor/text.py
+++ b/src/calibre/gui2/tweak_book/editor/text.py
@@ -836,7 +836,11 @@ class TextEdit(PlainTextEdit):
             c.setPosition(c.position() - len(suffix))
         self.setTextCursor(c)
 
-    def insert_image(self, href, fullpage=False, preserve_aspect_ratio=False):
+    def insert_image(self, href, fullpage=False, preserve_aspect_ratio=False, width=-1, height=-1):
+        if width <= 0:
+            width = 1200
+        if height <= 0:
+            height = 1600
         c = self.textCursor()
         template, alt = 'url(%s)', ''
         left = min(c.position(), c.anchor)
@@ -849,9 +853,9 @@ class TextEdit(PlainTextEdit):
                 template =  '''\
 <div style="page-break-before:always; page-break-after:always; page-break-inside:avoid">\
 <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" \
-version="1.1" width="100%%" height="100%%" viewBox="0 0 1200 1600" preserveAspectRatio="{}">\
-<image width="1200" height="1600" xlink:href="%s"/>\
-</svg></div>'''.format('xMidYMid meet' if preserve_aspect_ratio else 'none')
+version="1.1" width="100%%" height="100%%" viewBox="0 0 {w} {h}" preserveAspectRatio="{a}">\
+<image width="{w}" height="{h}" xlink:href="%s"/>\
+</svg></div>'''.format(w=width, h=height, a='xMidYMid meet' if preserve_aspect_ratio else 'none')
             else:
                 alt = _('Image')
                 template = '<img alt="{0}" src="%s" />'.format(alt)
diff --git a/src/calibre/gui2/tweak_book/editor/widget.py b/src/calibre/gui2/tweak_book/editor/widget.py
index 32a1281316..5122e7c8d9 100644
--- a/src/calibre/gui2/tweak_book/editor/widget.py
+++ b/src/calibre/gui2/tweak_book/editor/widget.py
@@ -228,8 +228,8 @@ class Editor(QMainWindow):
         func = getattr(self.editor, action)
         func(*args)
 
-    def insert_image(self, href, fullpage=False, preserve_aspect_ratio=False):
-        self.editor.insert_image(href, fullpage=fullpage, preserve_aspect_ratio=preserve_aspect_ratio)
+    def insert_image(self, href, fullpage=False, preserve_aspect_ratio=False, width=-1, height=-1):
+        self.editor.insert_image(href, fullpage=fullpage, preserve_aspect_ratio=preserve_aspect_ratio, width=width, height=height)
 
     def insert_hyperlink(self, href, text):
         self.editor.insert_hyperlink(href, text)
@@ -619,4 +619,3 @@ def launch_editor(path_to_edit, path_is_raw=False, syntax='html', callback=None)
         callback(t)
     t.show()
     app.exec_()
-