Wi-Fi-based indoor localization mechanisms have attracted many research efforts in recent years due to the widespread use of this technology. All robots in indoor scenarios use this technology to provide Internet connection for Cloud services in speech understanding or human-robot interaction. However, this technology can also be used to provide localization services based on the Received Signal Strength Indicator (RSSI). Nevertheless, the majority of the current proposed indoor localization systems spend huge amounts of time in order to set-up the system in the target environment. In addition, given that the IEEE 802.11 standards leave the RSSI computation up to the manufacturers, each device which needs to be located has to survey the wireless platform to correctly calibrate the localization system. To overcome these drawbacks, this paper presents a novel inter-device calibration procedure for new potential devices which makes use of a previous calibration carried out by a different device. The proposed calibration procedure enables an on-the-fly configuration of any new device with a negligible loss of localization accuracy.