The element variable tag {ce_count} is parsed inside every element tag pair and contains the element count for the current entry. This is a count of all elements, not just this specific element type.

Simplified case example:

{exp:channel:entries channel="your_channel" limit="10"}

	{custom_field}

		{heading}
			{value}
			<p>This entry has <strong>{ce_count}</strong> elements.</p>
		{/heading}

	{/custom_field}	

{/exp:channel:entries}