Kilocalorie (nutritional) to Kilograms of TNT

Most weight-loss guidelines recommend a deficit of 500 kcal/day below your maintenance level, which typically means 1,200–1,800 kcal/day for most adults. A 500 kcal/day deficit yields roughly 0.45 kg (1 lb) of fat loss per week, since one kilogram of body fat stores about 7,700 kcal. Going below 1,200 kcal/day is generally not recommended without medical supervision.

Almond cell walls are rigid and resist digestion — about 20% of the fat in whole almonds passes through the gut unabsorbed. A USDA study found that almonds provide ~129 kcal per 28 g serving, not the 170 kcal on the label. Walnuts and pistachios show similar discrepancies of 5–20%. Food labels use standard Atwater factors that assume full digestibility, which overestimates usable energy for structurally intact whole foods like nuts, seeds, and legumes.

The Atwater system assigns 9 kcal per gram of fat, 4 kcal per gram of protein, and 4 kcal per gram of carbohydrate. Alcohol provides 7 kcal/g. These rounded values have been the basis of food labeling since the 1890s. Actual digestibility varies — fiber-rich carbohydrates yield fewer usable kcal because the body cannot fully break them down.

A marathon (42.195 km) burns approximately 2,200–3,200 kcal depending on body weight, pace, and efficiency. A 70 kg runner typically burns about 2,600 kcal; an 85 kg runner about 3,100 kcal. That is roughly equivalent to 35 bananas or 13 slices of pizza. Elite runners complete the distance in about 2 hours, so their metabolic rate during the race exceeds 1,300 kcal/hour.

The International Table calorie (4.1868 J) was adopted by the Fifth International Conference on Properties of Steam in 1956 and became the standard for engineering and nutrition. The thermochemical calorie (4.184 J) was standardized earlier for chemistry. Nutritionists chose the IT value because food energy intersects more with engineering standards (steam tables, heating) than pure chemistry. The 0.07% difference is negligible for dietary purposes.

One kilogram of TNT releases 4.184 MJ — enough to shatter windows within several meters and cause serious injury at close range. In open air, 1 kg of TNT produces a blast overpressure lethal to humans within about 2–3 meters. The effect depends heavily on confinement: the same charge inside a vehicle or building is far more destructive than in open ground.

One kilogram of TNT (4.184 MJ) is roughly the kinetic energy of a 1,500 kg car traveling at 75 km/h, or the energy stored in about 120 mL (half a cup) of petrol. It is also the chemical energy in roughly one large meal (1,000 kcal). The difference is that TNT releases its energy in microseconds rather than hours.

Mining engineers express blast charge sizes in kg of TNT equivalent to standardize across different commercial explosives. A typical quarry blast hole uses 5–50 kg of ANFO (ammonium nitrate/fuel oil), equivalent to roughly 4–37 kg TNT. Building demolition charges range from 10 to several hundred kg TNT equivalent, carefully placed at structural weak points.

A standard 155 mm artillery shell contains about 7–11 kg of TNT equivalent. A 500 lb (Mk 82) air-dropped bomb holds roughly 87 kg of TNT equivalent. An RPG-7 warhead is about 1–2 kg TNT equivalent. Anti-tank mines range from 5–10 kg TNT equivalent. These figures represent explosive fill, not total weapon weight.

A standard stick of commercial dynamite (about 200 g, 20 cm long) has a TNT equivalence of roughly 0.25–0.30 kg, since dynamite is about 1.25–1.5× as powerful as TNT by weight. Eight sticks of dynamite are roughly equivalent to one kilogram of TNT. Modern mining rarely uses traditional dynamite, preferring cheaper ANFO or emulsion explosives.