Enter any 4 values to calculate the missing variable. This calculator uses a simplified adiabatic temperature-rise relation (constant effective specific heat capacity and no heat losses), which can be used as a rough estimate but is not a full combustion-equilibrium “true” adiabatic flame temperature calculation.

Adiabatic Flame Temperature Calculator

Enter any 4 values to calculate the missing variable (simplified constant-c estimate).

Adiabatic Flame Temperature Formula

A common simplified adiabatic temperature-rise estimate assumes a constant (average) specific heat capacity for the heated material/gases and that all of the input heat goes into raising temperature (no losses). Under those assumptions:

T_f = T_i + \frac{Q}{c \cdot m}

Variables:

  • Tf is the final (adiabatic) temperature (K)
  • Ti is the initial temperature (K)
  • Q is the net heat added to the material/gases being heated (J)
  • c is the effective (often average) specific heat capacity of the material/gas mixture being heated (J/kg·K)
  • m is the mass being heated (kg)

To estimate the final temperature, add the initial temperature to the heat input divided by the product of the effective specific heat capacity and the mass being heated.

What is Adiabatic Flame Temperature?

The adiabatic flame temperature is the temperature the combustion products would reach if reactants burned with no heat loss to the surroundings and (typically) at approximately constant pressure, with the released chemical energy converted into sensible internal energy of the products. In real combustion calculations, the adiabatic flame temperature depends on the fuel and oxidizer composition, the fuel–oxidizer ratio (stoichiometry/equivalence ratio), initial reactant temperature, pressure, temperature-dependent heat capacities of the products, and (at high temperature) chemical dissociation/equilibrium effects. The calculator above uses a simplified constant-specific-heat estimate and does not perform full combustion chemistry.

How to Calculate Adiabatic Flame Temperature?

The following steps outline how to calculate the simplified adiabatic temperature-rise estimate.

  1. First, determine the initial temperature (Ti).
  2. Next, determine the net heat added/released to the material or gases being heated (Q).
  3. Next, determine an effective (often average) specific heat capacity for the material/gas mixture over the temperature range of interest (c).
  4. Next, determine the mass being heated (m).
  5. Finally, calculate the final temperature using Tf = Ti + \(\frac{Q}{c \cdot m}\).
  6. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Initial Temperature (Ti) = 298 K

Heat Added/Released (Q) = 50000 J

Effective Specific Heat Capacity (c) = 1000 J/kg·K

Mass Heated (m) = 0.1 kg

Then Tf = 298 + \(\frac{50000}{1000 \cdot 0.1}\) = 298 + 500 = 798 K (about 525 °C). This is an illustration of the simplified energy-balance formula, not a typical hydrocarbon–air adiabatic flame temperature.