Can someone help me calculate how strong would these explosions be?

[StorytellingDemonKing]

So previously I asked in Questions and Answers but didn't get a response. Turns out you can ask here for help. So I will copy and paste the most important part.

The first explosion has a radius of 5 meters and an overpressure betwee five and seven kilos of force per square centimeter. So 1 low end and 1 high end.

Second explosion has a radius of 8.1 meters and overpressure of five and seven kilos of force per square centimeter.

What tier would these explosions be?

There aren't any scans because its from a Light Novel but I think it gave enough information to work for calculating how strong a character is. Too bad I'm horrible with math so help would be appreciated.

 

[Randomlamdom]

First low end is 0.05454965059 tons, high end is 0.08247159032 tons, both 9-a
Second low end is 0.23191936689 tons 9-a+, high end is 0.35063027547 tons 8-c

Using R^3*((27136*P+8649)^(1/2)/13568-93/13568)^2 from references for common feats