Adjust icon size of Floating action button (fab)

Question

The new floating action button should be 56dp x 56dp and the icon inside it should

Answer 1

off of @IRadha's answer in vector drawable setting android:height="_dp" and setting the scale type to android:scaleType="center" sets the drawable to whatever size was set

Answer 2

Try to use app:maxImageSize="56dp" instead of the above answers after you update your support library to v28.0.0

Answer 3

There are three key XML attributes for custom FABs:

• app:fabSize: Either "mini" (40dp), "normal"(56dp)(default) or "auto"
• app:fabCustomSize: This will decide the overall FAB size.
• app:maxImageSize: This will decide the icon size.

---

Example:

app:fabCustomSize="64dp" 
app:maxImageSize="32dp"

The FAB padding (the space between the icon and the background circle, aka ripple) is calculated implicitly by:

4-edge padding = (fabCustomSize - maxImageSize) / 2.0 = 16

---

Note that the margins of the fab can be set by the usual android:margin xml tag properties.

Answer 4

You can play with the following settings of FloatingActionButton : android:scaleType and app:maxImageSize. As for me, I've got a desirable result if android:scaleType="centerInside" and app:maxImageSize="56dp".

Answer 5

The design guidelines defines two sizes and unless there is a strong reason to deviate from using either, the size can be controlled with the fabSize XML attribute of the FloatingActionButton component.

Consider specifying using either app:fabSize="normal" or app:fabSize="mini", e.g.:

<android.support.design.widget.FloatingActionButton
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:src="@drawable/ic_done_white_24px"
   app:fabSize="mini" />

Answer 6

<ImageButton
        android:background="@drawable/action_button_bg"
        android:layout_width="56dp"
        android:layout_height="56dp"
        android:padding="16dp"
        android:src="@drawable/ic_add_black_48dp"
        android:scaleType="fitXY"
        android:elevation="8dp"/>

With the background you provided it results in below button on my device (Nexus 7 2012)

Looks good to me.