I have four buttons at the button of the screen and I want to keep the gaps between them as equal as possible. 

![enter image description here](https://i.stack.imgur.com/HHfTU.png)
This is how I place the buttons . 

![enter image description here](https://i.stack.imgur.com/SUP5i.png)
This is how they show up while I run it on emulator and the device.

Here's my xml code for the buttons.

```
    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" >

        <ImageView
            android:id="@+id/img_base"
            android:layout_width="fill_parent"
            android:layout_height="58dip"
            android:layout_alignParentBottom="true"
            android:background="@drawable/base" />

        <Button
            android:id="@+id/btn_gotoLocation"
            android:layout_width="43dip"
            android:layout_height="50dip"
            android:layout_alignParentBottom="true"
            android:layout_alignParentLeft="true"
            android:layout_marginLeft="16dp"
            android:background="@drawable/location" />

        <Button
            android:id="@+id/calculate"
            android:layout_width="43dip"
            android:layout_height="50dip"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:layout_marginRight="23dp"
            android:background="@drawable/cal" />

        <Button
            android:id="@+id/btn_info"
            android:layout_width="43dip"
            android:layout_height="50dip"
            android:layout_alignParentBottom="true"
            android:layout_marginRight="25dp"
            android:layout_toLeftOf="@+id/calculate"
            android:background="@drawable/info" />

        <ImageView
            android:id="@+id/add_place"
            android:layout_width="50dip"
            android:layout_height="60dip"
            android:layout_alignParentBottom="true"
            android:layout_marginRight="36dp"
            android:layout_toLeftOf="@+id/btn_info"
            android:src="@drawable/add_place" />

    </RelativeLayout>

```

How can I fix this problem?