Erin Onsager is the founder of Simply Spreadsheets, where she combines her passion for financial forecasting, budgeting, and income/expense tracking with a mission to help clients and small businesses streamline their data and achieve financial success. Erin brings a unique blend of strategic insight and hands-on experience to every project, with a particular joy in empowering others to elevate their financial acumen.
Beyond Simply Spreadsheets, Erin is a successful residential real estate investor with a proven track record of achieving profits from every investment within five years. For over a decade, she has been deeply involved in residential real estate investing, where she mentors and coaches individuals eager to explore the field, balancing a keen eye for opportunities with practical, real-world experience.
A graduate of the University of Chicago with a degree in Economics, Erin boasts over two decades of expertise in commercial real estate, encompassing mortgage brokerage, lending, asset management, and private equity.
When not immersed in spreadsheets or real estate ventures, Erin enjoys cooking, hosting dinner parties, traveling, and camping with her dog.
What Clients Say
“Simply Spreadsheets transformed how we manage our finances at GC Joe. Erin took our budgeting and cash flow processes and turned them into clear, organized systems that actually make sense. She’s responsive, reasonable, and has a real gift for making complex financial data digestible for non-numbers people. We’ve maintained an ongoing relationship with Erin because the value she brings is consistent — I’d recommend her to any business owner looking to get a real handle on their numbers.”
— Joe Whitehead, Esq., Owner, GC Joe
“Erin took a complex reporting process that used to eat up hours of my time and built a spreadsheet that now takes mere minutes to update. What used to be one of the most tedious parts of my week is now practically effortless. She understood exactly what I needed and delivered a solution that just works.”
— Mark Dally, Asset Accountant
Ready to Work Together?
Whether you need custom spreadsheets, real estate coaching, or strategic consulting, we’d love to help you reach your goals.
Simply Spreadsheets 