Eco Fuel Briquettes

All manufacturers of eco briquettes, or wood briquettes, sawdust briquettes and eco logs, pack and offer their produce, labelled with mysterious technical information: kcal / kg or kcal / kg. The average consumer does not have this terminology in their heads and most of them are used to convert the energy they can get from the electrical company, using kilowatt hour (kw h), because almost everyone knows how much a kw hr costs, purchased from the electrical companies.
However, what is the kilocalorie used on a pack of eco briquettes / wood briquettes or eco logs?
One kilocalorie is equal to 1000 calories.
Kcal / kg means that if it says on the label for example 4.23 kcal / kg and an eco briquette weighs 1 kilogram, the energy output from burning will be the equivalent of 4230 calories.
Is it a lot or too little?
The relationship between Calorie and Joule is:
1 cal = 4,184 J
1 J = 0,239 cal

1 J or one joule is a unit of energy.

3600000 J are equal to one kw h. So for example if 1 kw h of energy costs 0.20 EUR, then we can say that we pay the same for 3,600,000 joules of energy.

An average eco briquette has an energy efficiency of 4200 to 5300 kcal / kg or 4.2 to 5.3 mega calorie per kg, which is equivalent of between 4,200,000 to 5,300,000 calories per kilogram. We multiply calories by 4.18 and divide by 3,600,000 in order to arrive at kw h. If we start from mega calories per kg and want to convert to kw h, we multiply by 4.18 and divide by 3.6 or mega calories are multiplied by 1.61 to arrive at kw h.

By the above calculations an eco briquette with energy efficiency from 4.2 to 5.2 mega cal / kg gives out energy from the combustion from 4.87 to 5.72 kw h per kilogram. If one eco briquette weighs 2 kg, then the energy is twice as much.
This turned into cash at a price of 0.20 EUR for 1 kw h gives an energy of about 1 to 1.20 EUR.