While Dimensions includes the largest (and perhaps the only global) database for awarded research grants, it is of course not possible to cover grants from every possible funder, for several reasons:

• many funders don't publish or allow access to their grants data
• many funders don't allow vendors to process their grants data for commercial purposes
• many funders may publish grants data, but in a format that is not machine-readible or of a quality that doesn't allow for inclusion in a structured database

As there's also no complete list of funders worldwide available, it's difficult to impossible to say how (relatively) large the coverage of Dimensions is. What we can say is that we have awarded grants data for more than 7m grants from ca. 700 funders from all over the world, totalling ca. $2.6tn (note though that some funders don't publish funding amounts).