The Internet consultancy estimated that a company with one of the least-usable intranet designs would spend £1,925 per employee annually on 16 common tasks. The most usable designs would cost just £989 per employee.
The research estimated total annual costs for companies with more than 10,000 employees at £9.9m if they have good intranet usability; £13.1m with average and £19.2m with bad usability.
If all company intranets were as good as the best 25% in the study, the global economy would save £197bn on the 16 tasks alone, it said.
Jacob Nielsen, co-founder of Nielsen Norman Group, said intranets are as important as corporate Web sites.