Android: How to change CheckBox size?

You just need to set the related drawables and set them in the checkbox:

<CheckBox 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"
    android:text="new checkbox" 
    android:background="@drawable/my_checkbox_background"
    android:button="@drawable/my_checkbox" />

The trick is on how to set the drawables. Here's a good tutorial about this.

You can try the following solution to change the size of custom checkbox by setting the following properties to Checkbox in your layout file. Worked for me

android:scaleX="0.8" android:scaleY="0.8"

android:button="@null"
android:scaleX="0.8"
android:scaleY="0.8"
android:background="@drawable/custom_checkbox"

add following lines to drawable file

<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item android:state_checked="false"
      android:drawable="@drawable/unchecked_img" />
<item android:state_checked="true"
      android:drawable="@drawable/checked_img" />
</selector>

use this code.

in layout:

<CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:button="@drawable/my_checkbox"  *** here
        android:checked="true"/>

add a new drawable : my_checkbox.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item
    android:state_checked="false"
    android:drawable="@drawable/checkbox_off_background"/>

<item
    android:state_checked="true"
    android:drawable="@drawable/checkbox_on_background"/>

and end create 2 drawable :

checkbox_off_background.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android">

<item>
    <shape android:shape="rectangle">
        <size
            android:height="25dp"   *** your size
            android:width="25dp"/>
    </shape>
</item>

<item android:drawable="@android:drawable/checkbox_off_background"/>

and too, checkbox_on_background.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android">

<item>
    <shape android:shape="rectangle">
        <size
            android:height="25dp"
            android:width="25dp"/>
    </shape>
</item>

<item android:drawable="@android:drawable/checkbox_on_background"/>

I could not find the relevant answer for my requirement which I figured it out. So, this answer is for checkbox with text like below where you want to resize the checkbox drawable and text separately.

You need two PNGs cb_checked.png and cb_unchechecked.png add them to drawable folder

Now create cb_bg_checked.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/cb_checked"
        android:height="22dp" <!-- This is the size of your checkbox -->
        android:width="22dp"  <!-- This is the size of your checkbox -->
        android:right="6dp"   <!-- This is the padding between cb and text -->
        tools:targetApi="m"
        tools:ignore="UnusedAttribute" />
</layer-list>

And, cb_bg_unchecked.xml

 <?xml version="1.0" encoding="utf-8"?>
    <layer-list xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools">
        <item android:drawable="@drawable/cb_unchechecked"
            android:height="22dp" <!-- This is the size of your checkbox -->
            android:width="22dp"  <!-- This is the size of your checkbox -->
            android:right="6dp"   <!-- This is the padding between cb and text -->
            tools:targetApi="m"
            tools:ignore="UnusedAttribute" />
    </layer-list>

Then create a selector XML checkbox.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/cb_bg_checked" android:state_checked="true"/>
    <item android:drawable="@drawable/cb_bg_unchecked" android:state_checked="false"/>
</selector>

Now define it your layout.xml like this

<CheckBox
  android:id="@+id/checkbox_with_text"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:checked="true"
  android:button="@drawable/checkbox"
  android:text="This is text"
  android:textColor="@color/white"
  android:textSize="14dp" /> <!-- Here you can resize text -->

Assume your original xml is:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true"
        android:drawable="@drawable/tick_img" />
    <item android:state_checked="false"
        android:drawable="@drawable/untick_img" />
</selector>

then simply remove android:button="@drawable/xml_above" in your checkbox xml, and do drawable scaling programmatically in java (decrease the 150 big size to your desired dp):

CheckBox tickRememberPasswd = findViewById(R.id.remember_tick);

//custom selector size
Drawable drawableTick = ContextCompat.getDrawable(this, R.drawable.tick_img);
Drawable drawableUntick = ContextCompat.getDrawable(this, R.drawable.untick_img);
Bitmap bitmapTick = null;
if (drawableTick != null && drawableUntick != null) {
    int desiredPixels = Math.round(convertDpToPixel(150, this));

    bitmapTick = ((BitmapDrawable) drawableTick).getBitmap();
    Drawable dTick = new BitmapDrawable(getResources()
            , Bitmap.createScaledBitmap(bitmapTick, desiredPixels, desiredPixels, true));

    Bitmap bitmapUntick = ((BitmapDrawable) drawableUntick).getBitmap();
    Drawable dUntick = new BitmapDrawable(getResources()
            , Bitmap.createScaledBitmap(bitmapUntick, desiredPixels, desiredPixels, true));

    final StateListDrawable statesTick = new StateListDrawable();
    statesTick.addState(new int[] {android.R.attr.state_checked},
            dTick);
    statesTick.addState(new int[] { }, //else state_checked false
            dUntick);
    tickRememberPasswd.setButtonDrawable(statesTick);
}

the convertDpToPixel method:

public static float convertDpToPixel(float dp, Context context) {
    Resources resources = context.getResources();
    DisplayMetrics metrics = resources.getDisplayMetrics();
    float px = dp * (metrics.densityDpi / 160f);
    return px;
}

If you want to add a custom image to checkbox then set button to null and just add background to checkbox that's solve

 <CheckBox
    android:layout_width="22dp"
    android:layout_height="22dp"
    android:layout_marginLeft="-10dp"
    android:button="@null"
    android:background="@drawable/memory_selector"/>