Well...

I had planned on doing this... ages ago really.

Here's the actual result

Spoiler:

Here's the Feat in its entirety and Result

Right here we have how Meruem enjoyed the experience

The fact about half his body was intact, if not severely burnt, is still a solid feat of durability, just warrants a fraction of the whole *shrugs*

Spoiler:

You can get the size of the hill I measured here.

Hill Height = 152 pixels
Crater Diameter = 1461 pixels

Crater Diameter/Hill Height = 9.612

Hill Height (Method 1) = 104.212 meters
Hill Height (Method 2) = 95.636 meters

Crater Diameter (Method 1) = 1,001.686 meters
Crater Diameter (Method 2) = 919.253 meters

Volume = (2/3)PIr1^2r2

r1 = Crater/2
r2 = Crater/4

Crater Volume (Method 1) = 131,496,204.679 m^3
Crater Volume (Method 2) = 101,630,385.745 m^3

6147 j/cc (its described as melted)
30342 j/cc (note the sizz SFX to denote vapor)

Rose Bomb Yield (Method 1; Low End) = 808,307,170,161,813,000 joules or 193.19 megatons
Rose Bomb Yield (Method 1; High End) = 3,989,857,842,370,218,000 joules or 953.599 megatons

Rose Bomb Yield (Method 2; Low End) = 624,721,981,174,515,000 joules or 149.312 megatons
Rose Bomb Yield (Method 2; High End) = 3,083,669,164,274,790,000 joules or 737.015 megatons

I could subtract the volume I got for Netero's Hyakushiki Crater Scaling, but I don't see the need when Netero likely took down enough hills with the rose for it not to matter much.

Nor do I feel like it right now anyway.

Final Tally

Rose Bomb Yield (Method 1; Low End) = 193.19 megatons
Rose Bomb Yield (Method 1; High End) = 953.599 megatons

Rose Bomb Yield (Method 2; Low End) = 149.312 megatons
Rose Bomb Yield (Method 2; High End) = 737.015 megatons