Convert Calories to Kilotons of TNT

Convert Calories (cal) to Kilotons of TNT (kt(TNT)) instantly and accurately.

Calories (cal)
Kilotons of TNT (kt(TNT))

Conversion Formula

kt(TNT) = cal × 1.000000000e-12

About Calories

A calorie (cal) - the thermochemical calorie - is exactly 4.184 J, defined as the heat to raise 1 g of water by 1°C. Standard since 1954. The calorie is the fundamental unit of heat measurement in thermochemistry: glucose combustion releases 669.9 kcal/mol; water vaporisation requires 539.7 cal/g. Bond dissociation energies in quantum chemistry are often quoted in kcal/mol. Note: the dietary Calorie (capital C) on food labels is 1 kcal = 4,184 J - a factor-of-1,000 difference that causes persistent confusion. 1 cal = 4.184 J = 1.163 × 10⁻³ Wh.

About Kilotons of TNT

A kiloton of TNT (kt(TNT)) = 10³ tons of TNT = exactly 4.184 TJ. It is the standard unit for sub-megaton nuclear weapon yields. Hiroshima's Little Boy: ~12-18 kt; Nagasaki's Fat Man: ~19-23 kt. The W88 warhead (Trident II) is ~475 kt; the W76 is ~100 kt. The Beirut port explosion (2020): estimated 0.5-1.1 kt. A magnitude 5.0 earthquake releases ~0.5-2 kt of seismic energy. A kiloton blast creates a fireball ~90-100 m radius and a lethal thermal radius of ~1-2 km. 1 kt(TNT) = 4.184 TJ = 1,162.8 MWh.

Quick Reference Table

Calories (cal)Kilotons of TNT (kt(TNT))
1 cal1 × 10-12 kt(TNT)
2 cal2 × 10-12 kt(TNT)
5 cal5 × 10-12 kt(TNT)
10 cal1 × 10-11 kt(TNT)
25 cal2.5 × 10-11 kt(TNT)
50 cal5 × 10-11 kt(TNT)
100 cal1 × 10-10 kt(TNT)

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