A Nickel Bioavailability Tool (NiBAT) has been developed that simplifies the integrated NiBLM (Biotic Ligand Model) but runs in MS Excel. It requires data input for site-specific dissolved organic carbon, pH and calcium. The NiBAT uses an algorithm and constants which can be readily automated within Laboratory Information Management Systems. The performance of this NiBAT compared with the integrated NiBLM is reviewed and discussed in this report. Guidance on the use of the NiBAT and interpretation of the outputs from the tool, including screenshots, is also provided.