Soot emissions from combustion devices are known to have harmful effects on the environment and human health. This project leverages existing knowledge in soot modelling and soot formation fundamentals to develop a stand-alone, computationally inexpensive soot concentration estimator to be linked to CFD simulations as a post-processor. The estimator consists of a library generated using the hystereses of soot-containing fluid parcels, which relates soot concentration to the aggregated gas-phase environment histories to which a fluid parcel has been exposed. The estimator can be used to relate soot concentration to computed parcel hystereses through interpolation techniques. The estimator shows the potential ability to produce accurate predictions with very low computational cost in laminar coflow diffusion flames. Results also show that as flame data representing a broader set of conditions is added to the library, the estimator becomes applicable to a wider range of flames.