Credits to Xeno
Shin Godzilla's radiation heat ray:
In this picture, we see Shin Godzilla destroying skyscrapers with his radiation heat ray.
I'm using the tallest skyscraper on screen here.
Mass Assuming the skyscraper is 120 meters tall since it looks like it's as tall as Shin Godzilla as it's shown.
Skyscraper's height = 205 px = 120 meters
Skyscraper's length = 53 px = 31.0243902439 meters
Skyscraper's width = 13 px = 7.6097560976 meters
Skyscraper's volume = 28,330.565139941 m3
Carbon Steel density = 7,663 kg/m3
Mass = Volume × Density Mass = 28,330.565139941 × 7,663 = 217,097,120.66737 kg Heat
The melting point of Carbon Steel is 1,540℃
However i'll multiply it by 4 due to the facility for Shin Godzilla to melt it.
1,540 × 4 = 6,160℃ A steel is close to 20℃
Temperature change = 6,160 - 20 = 6,140℃
Specific heat capacity of a carbon steel is 502.416 J/(kg*K)
Specific Heat Energy Specific Heat Energy = (217,097,120.66737 × 6,140) × 502.416 = 6.6970863E+14 Joules = 160.064204407 Kilotons (Large Town level)
Since the buildings Shin Godzilla melted were approximately 15, i'll multiply the energy by it 6.6970863E+14 × 12 = 1.0045629E+16 Joules = 2.40096306611 Megatons (Small City level)