TNT Equivalent Calculator
This TNT equivalent calculator will help you find the TNT equivalent weight for different explosives. Using this calculator, you can find answers to questions like how many kilograms of C4 produces energy equivalent to 1 kg of TNT.
There was a need to adopt a universal quantity to compare the energy output of various explosives. TNT (trinitrotoluene) equivalent weight was chosen because its blast characteristics resemble most solidtype explosives. Blast characteristics data is crucial to design protective structures, and the number of explosives help determine the pressure loads (see blast radius calculator) acting on the structures during an explosion event. In addition to this, it is also used as a unit of energy conversion (see energy conversion calculator).
Read on to understand how to calculate TNT equivalence using our tool.
TNT Equivalence
TNT equivalence is a function of the ratio of heat produced during detonation. A kilogram of TNT produces $4.184$ MJ of energy. For an explosive having a heat of detonation $H_\mathrm{exp}$, the TNT equivalent weight $W_\mathrm{eq}$ is:
where the heat of detonation is expressed in $\mathrm{MJ/kg}$ and weight is in $\mathrm{kg}$. The ratio of heat of detonation is called the TNT factor. The table below contains some of the common explosives and their heat of detonation:
Explosive  Heat of detonation (MJ/kg)  Factor 

TNT  4.184  1.000 
Baratole  2.209  0.528 
Comp B  4.566  1.091 
C4  4.715  1.127 
HMX  4.821  1.152 
Pentolit 50/50  4.545  1.086 
PBX 9407  4.757  1.137 
PETN  4.906  1.173 
RDX  4.821  1.152 
Tetryl  4.481  1.071 
NQ  3.165  0.756 
NG  4.715  1.127 
Ammounium nitrate  1.757  0.420 
ANFO  3.682  0.880 
Natural gas  0.669  0.160 
Ammonium picrate  4.058  0.970 
HBX3  4.268  1.020 
Torpex  5.021  1.200 
Tritonal  3.891  0.930 
Amatol 80/20  4.895  1.170 
Tetrytol 75/25  5.021  1.200 
Torpex  5.021  1.200 
Did you know?
Only onethird of the chemical energy is released upon detonation; the rest is released at a slower rate as the explosive burns through, which is a function of heat of combustion.
How to calculate TNT equivalent
Now that you know what is TNT factor is, we will use it to calculate TNT equivalences. You can do that using the accompanying tool.
 Enter the heat of detonation of the explosive.
 Insert the heat of detonation for 1 kg of TNT ($4.184~\mathrm{MJ/kg}$).
 Fill in the weight of the explosive.
 The calculator will return the TNT factor and TNT equivalent weight.
We have already input data for some common explosives. Click on the dropdown list to pick one.
Using the TNT equivalent calculator
Using our calculator, let's calculate the TNT equivalent weight of 6.5 kg of C4.
To calculate the TNT equivalent weight:

Select "C4" from the list of explosives.

The calculator sets the heat of detonation as
4.71 MJ/kg
and4.184 MJ/kg
for C4 and TNT, respectively. 
The TNT factor is:

Enter the weight of C4 as
6.5 kg
. 
You can obtain the TNT equivalent weight by multiplying the factor with the weight of C4:
FAQ
What is TNT?
TNT is one of the most commonly used explosives for military and mining operations. It stands for "2,4,6trinitrotoluene". One kg of TNT releases 4.184 MJ of energy upon detonation. This value helps compare various highenergy events.
What is TNT equivalent factor?
TNT equivalent factor is a physical quantity used to compare explosives based on their heat of detonation. It was adopted as a benchmark because blast characteristics resemble most solidtype explosives. Mathematically, it is the ratio of heat of detonation of explosive and TNT.
How do I calculate TNT equivalent factor?
To calculate TNT equivalent factor:

Find the heat of detonation of the explosive in kJ/kg.

Divide the heat of the detonation of the explosive by the heat of the detonation of TNT (4,184 kJ/kg) to obtain the TNT equivalent factor.
How much TNT is equivalent to 3 kg of C4?
3 kg of C4 has the TNT equivalent weight of 3.381 kg of TNT. Using the heat of detonation of C4 and TNT as 4.71 MJ/kg
and 4.184 MJ/kg
, respectively:
Wexp = 3 × 4.71/4.184 = 3.381 kg of TNT
.