Working out Break Even point with many entries on the Pair

Edit: Title meant to be:
"Working out Break Even point with many entries on the Pair", (Admin feel free to edit it )

I am wondering if there is a quick easy way to work out my Break Even point when I have many trades open on a single pair all going in the one way.

Eg, I long EUR/USD

0.1 Lot at 1.7800
Price goes against me and I add to the trade
0.1 Lot at 1.7750
0.1 Lot at 1.7700
0.3 Lot at 1.7600


So each at 0.1 Lot is simply add the entry price then dived by the number of trades, but what about when you put in 0.3lots ?

Is there a simple calculation or EA to show you the Break Even as the average BE price becomes lower as I add to the trade.

Maybe this?

Here is the logic so you can see how to manually calculate it.

You already know for 3 entries each of 0.1 lot that you add the vales and divide by 3.
(E1 + E2 +E3) / 3
But this can be rewritten as
(1 × E1 / 3 ) + (1 × E2 / 3) + (1 × E3 / 3)

So out of the TOTAL of 3 entries, each entry contributes 1/3 of its value. Likewise, for other lot sizes, first sum the number of lots, then use the corresponding lot size, like so.
E1, E2, E3 are each 0.1 lot, which we are calling 1 mini lot. And E4 is 3 minilots.
So, a total of 6 mini lots.
So here are the contributions
(1 × E1 / 6) + (1 × E2 / 6) + (1 × E3 / 6) + (3 × E4 / 6)