The calculator is a piece of software (often an .exe or Python script) that takes your IMEI, applies the v4 or v5 algorithm, and spits out an unlock code in seconds.
Finding official or safe download links for these calculators can be difficult as they are often third-party tools. Use caution when downloading from unofficial sources. Huawei V4 And V5 Unlock Code Calculator By Imei huawei v4 and v5 unlock code calculator download link