According to Official Guinness Records,
The largest whiteboard measures 114.3 m² (1230.31 ft²), achieved by Abu Dhabi Health Services Company - SEHA (UAE), in Al Ain, United Arab Emirates, on 25 February 2017. The white board was made during the company's 'innovation week' events. The measurement and presentation of the white board occurred in a charity ceremony organised by SEHA to celebrate their 'year of giving'.
For a complete list of 2017 records, please visit 2017 Guinness Records in United Arab Emirates.