GBA requested this, btw.
https://www.youtube.com/watch?v=XZ4pDHSXsqc&feature=youtu.be&t=28m44s
Measuring both the Earth's diameter gives the 307 pixels, while the beam is 85 x 76 pixels.
Next we divide 12,742 by 307.
12742 / 307 = 41.5048859935
So that's the diameter of the beam. Now I just square it.
41.5048859935² = 1722.65556133, and now I have to multiply that by the diameter of the Earth.
1722.65556133 x 12,742 = 21950077.1625, now I need the amount of cubic centimeters of rock that was vaporized.
Converting 21950077.1625 km^3 into cm^3, I get 2.195008e+22 cm^3.
Next I divide 2.195008e+22 by the amount of joules in one ton of TNT, which is 4,184,000,000.
2.195008e+22 / 4,184,000,000 = 5.246195e+12, which is how many tons of TNT it is. The 'e+12' prefix is equal to tera on the metric prefix table, meaning it's about 5 teratons.
Woo, Small Country Level+ KND.
Final Tally
Father's breath = 5.24 teratons of TNT equivalent.