TNT Equivalent Calculator — Energy to Explosive Yield
Convert any energy release — from a chemical reaction, nuclear explosion, asteroid impact or electrical system — into its TNT equivalent mass. The result is shown in grams, kilograms, metric tons, kilotons and megatons of TNT.
Energy unit
Energy expressed as an equivalent mass of TNT explosive
Convert input to joules using the unit factor
Apply the TNT definition: 1 g TNT = 4,184 J
Divide joules by joules per metric ton of TNT
- 1
Convert to joules
4.184 GJ × 1,000,000,000 = 4,184,000,0001 GJ = 1,000,000,000 J (the unit conversion factor). - 2
Divide by 4,184 J/g (TNT definition)
4,184,000,000 ÷ 4184 = 1,000,000 - 3
Convert grams to metric tons (÷ 10⁶)
1,000,000 ÷ 1,000,000 = 1
How does this calculator work?
TNT equivalent converts energy to a mass of TNT using the defined constant 1 g TNT = 4,184 J. Divide any energy in joules by 4,184 to get grams of TNT; divide by 4.184 × 10⁹ to get metric tons. For reference: 1 kt TNT = 4.184 TJ; 1 Mt TNT = 4.184 PJ. The 4,184 J/g figure is a defined convention, not the actual TNT detonation energy (~4,500 J/g).
Formula
How this is calculated
The TNT equivalent is a unit of energy used to describe the yield of large explosions, particularly nuclear weapons, asteroid impacts and industrial accidents. It is defined by convention: 1 gram of TNT releases exactly 4,184 joules of energy (thermochemical calories). This is a defined standard, not a measured average — actual TNT detonation releases approximately 4,600 J/g, but the conventional figure 4,184 J/g was adopted by IUPAC for its round-number convenience and relationship to the calorie.
To convert any energy to TNT equivalent, divide the energy in joules by 4,184 to get the equivalent mass in grams. The calculator handles joules, kilojoules, megajoules, gigajoules, terajoules, kilowatt-hours, calories and kilocalories. For reference: a lightning bolt releases roughly 1 GJ (≈ 239 kg TNT); a Hiroshima-type bomb released about 63 TJ (≈ 15 kt TNT); a 1 Richter-unit increase in earthquake magnitude corresponds to about 31.6 times more energy.
Scale caution: TNT equivalents span many orders of magnitude. A grenade contains a few hundred grams of explosive (≈ 0.5 MJ); a strategic nuclear warhead carries hundreds of kilotons (hundreds of terajoules). The scientific notation display helps compare values at very different scales. This calculator uses metric tons throughout (1 metric ton = 1,000 kg); note that the US "short ton" (2,000 lb) is 0.907 metric tons.
Frequently asked questions
The 4,184 J/g figure is a conventional standard, not the actual heat of detonation of TNT (which is approximately 4,520–4,600 J/g depending on the explosive grade and confinement). The figure 4,184 was chosen because it equals 1,000 thermochemical calories/g — a round-number convention adopted internationally. All published nuclear yield figures use this definition.
The Hiroshima bomb yielded about 12–18 kt TNT (estimates range; US DOE uses 15 kt). A typical modern warhead in a strategic missile is 100–500 kt; the largest nuclear test ever, the Soviet Tsar Bomba, yielded approximately 50 megatons (50,000 kt). One kiloton equals 4.184 × 10¹² J (4.184 TJ).
Yes. Seismic moment magnitude M relates to energy by E ≈ 10^(1.5M + 4.8) joules. Enter that joule value here to get the TNT equivalent. A magnitude 7.0 earthquake releases roughly 2 × 10¹⁵ J ≈ 480 kilotons TNT. Note that seismic energy is only a fraction of the total energy released in a rupture.
Also known as
TG we-Calculate Editorial Team. (2026). TNT Equivalent Calculator — Energy to Explosive Yield [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/tnt-equivalent-calculator
TG we-Calculate Editorial Team. "TNT Equivalent Calculator — Energy to Explosive Yield." TG we-Calculate. 2026. https://we-calculate.com/calculator/tnt-equivalent-calculator.
TG we-Calculate Editorial Team, "TNT Equivalent Calculator — Energy to Explosive Yield," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/tnt-equivalent-calculator
@misc{wecalculate_tnt_equivalent_calculator, title = {TNT Equivalent Calculator — Energy to Explosive Yield}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/tnt-equivalent-calculator}}, year = {2026}, note = {TG we-Calculate} }
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