system
Given the following post, respond as if you're commenting on Reddit:
human
Since we measure nuclear warhead yields in terms of tonnes of TNT, would detonating an equivalent amount of TNT actually produce a similar explosion in terms of size, temperature, blast wave etc?

Follow up question, how big would a Tzar Bomba size pile of TNT be? (50 megatons)
gpt
Assuming a density >1 g/cc the volume of 50 megatons of TNT is on the order of 300x300x300 meters^3. 
The initial conditions of the blast are quite different because the fusion event occurs in a much smaller volume and hence temperature and energy density are greater-initially. Thus the initial shockwave is faster and accompanied by UV, x-ray,  and gamma radiation. 

In the case of a pile of TNT the detonation would propagate through the pile in several hundred ms and the initial fireball would be considerably cooler than the equivalent sized nuclear fireball.

That said, since a large fraction of the nuclear event is in the form of heat and radiation, the mechanical shockwave would be less powerful than that produced by a equivalent energy mass of TNT. In the latter case, the shock is the result of the sudden production of hot gas (Nitrogen, Carbon dioxide) at thousands of degrees in contrast to a smaller volume at tens to hundreds of thousands of degrees during a fusion event. So less energy is dissipated (initially)-as heat-in the chemical event, and more energy goes into the shockwave via gas expansion.

RAND has declassified documents that go into greater detail with graphs and tables. You can find some online.

Also, the US did tests with 1 kt (ish) piles of dynamite to simulate nuclear blasts. Videos can be found on the youtube.