Charles Williams

Microsoft MVP, United Kingdom

Microsoft MVP for Excel since 2009. Charles is an Excel expert who specializes in performance — he is a world leader at making Excel go faster. Once of his specialties is making your VBA UDFs (User Defined Functions) more efficient. After leaving IBM in 1996, he founded a Microsoft Office consultancy and software development company – Decision Models. His special interest areas are: Excel Calculation performance, VBA UDFs & VBA Performance, Excel JS API, Large Excel model,  Excel Defined Names, Excel as frontend to Relational Databases, C++ XLLs.

Charles is co-author with Jan Karel Pieterse of Name Manager, a widely-used utility for managing Excel defined names, and author of FastExcel, a commercial product to help optimize Excel calculation speed.

Charles’ Lecture Title: “Make your VBA run 100x Faster”

The way you write VBA can have a huge impact on speed. Charles will show a few simple tricks you can use to make your VBA fast, both for macros and User Defined Functions. You will learn the importance of transferring data efficiently between Excel and VBA, how to call worksheet functions from VBA, how to write efficient UDFs, and how to use arrays to speed up your processing.