Users select a fuel, volume units, a quantity, and hit solve. A gallon of liquid hydrogen, for instance, has about as much energy as a pint of gas. The calculator was developed by Shec-Labs, (Solar Hydrogen Energy Corporation), in Saskatoon, Saskatchewan, Canada (sheclabs.com). The research lab says it also develops solar-powered devices that produce hydrogen by the disassociation of water.
The calculator works for fuels including hydrogen, natural gas, gasoline, coal, and butane, as liquids and as gas at several pressures. The calculator is accessible free at sheclabs.com/calc/fuel_energy_equivalen ce.php