A theoretical method was optimized based on a wrinkled flame model for predicting the explosion pressure in confined chambers for typical low-carbon fuels, e.g., hydrogen (H2), methane (CH4), and ammonia/dimethyl ether/hydrogen (NH3/DME/H2) blends, etc. It was found that the previous model with a wrinkling factor of ΞΔ=et (t is time) is only applicable to the explosions of H2 fuel, while considerably underestimating the explosion pressures of other fuels such as CH4 and NH3/DME/H2 blends. For H2 fuel where the pressure power exponent β > 0, the effect of flame wrinkling on the laminar burning velocity SL is less significant compared to that of adiabatic compression, so that an underestimated wrinkling factor does not affect the overall prediction of pressure by the model. However, for most fuels with β < 0, a more accurate representation of the wrinkling effect is necessary for pressure prediction. The results show that the model can be optimized by increasing the wrinkling factor to ΞΔ=e20t that satisfactorily represents the effect of flame instabilities. The wrinkling factor remains constant (ΞΔ=2.46) after it reaches its maximum value of 2.46. Comparison of the model predictions to experiments shows that the optimized model can well predict the explosion pressures of various low-carbon fuels that experienced flame instability.