Ever wondered how much energy would hit a starship if you detonated a large nuclear bomb in its vicinity? Well, the Blast Intensity Calculator will tell you exactly that. You will need to supply the estimated surface area of the ship which faces the bomb, though. The result of the calculator is the upper limit on the energy that the bomb could deliver to the ship.
The calculator divides the energy released by the surface area of a sphere with a radius equal to the distance from the explosion. The result is the amount of energy from the bomb that would strike one square meter of surface area at that distance.
Of course, the surface area of a ship is not actually flat, let a lone a curved surface that matches the curve of this imaginary sphere, but at large distances, the differences between the two will reduce to a negligible amount. Therefore, if you know the area of the ship's "silhouette", you can determine how much energy from the bomb will strike it. Some of the energy will undoubtedly reflect off the target, so this calculation produces an approximate upper limit on the amount of energy the target can absorb.