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}