Now booking 2026 speaking engagements: small business finance, real estate, personal money, side hustles. See topics →
Strategic Financial Leadership, Right-Sized for Your Business
Fractional CFO and ad hoc finance support for owner-operated small businesses, plus real estate investors who want sharper numbers. 20+ years of senior-level finance experience, right-sized for your business. Bookkeeping, cash flow, reporting, and strategy under one roof.
WHAT WE DO
Financial Strategy for Any Business, Any Size, Any Stage
From solo founders and small businesses to growing portfolios and personal finances, wherever you need sharper numbers, I’m built to step in.
Fractional CFO
Senior-level financial strategy and oversight without the cost of a full-time hire. Cash flow management, reporting, budgeting, and bookkeeping for growing businesses.
Consulting
Strategic partnership for businesses that need custom spreadsheets, dashboards, and financial systems built from the ground up – tailored to your operations.
Personal Finance Coaching
One-on-one guidance for individuals, real estate investors, and small business owners ready to take charge of their numbers. Personal budgets, investment strategy, debt payoff, retirement planning, and rental property analysis.
Speaking Engagements
Keynotes, workshops, and podcasts on small business finance, real estate investing, personal money basics, and side hustles. Plain-English talks for chambers, conferences, and corporate audiences.
TEMPLATES
Ready-made tools. Built by a strategist.
Professional-grade financial spreadsheets built from 20+ years of real-world experience. Plug in your numbers, get instant clarity, and make confident decisions. Every template is the same tool we use with our own clients.
Small Business Owners
Annual budgets, cash flow forecasting, and expense tracking. Built for owners who want to understand their numbers without hiring a full-time accountant.
Real Estate Investors
Rental property analysis, BRRRR strategy calculators, house flip P&L tools, portfolio trackers, and a landlord tax deduction template. Everything you need to evaluate deals, manage your holdings, and maximize your write-offs at tax time.
WHY CHOOSE US
Your Data Deserves Someone Who Gets It
Simply Spreadsheets is led by Erin Onsager, a fractional CFO and financial strategist with 20+ years of senior finance experience across small business operations, commercial real estate, and institutional investing. From running the books for owner-operated businesses like Casa Marcelo to evaluating multi-million-dollar real estate deals, Erin brings the same hands-on rigor to every engagement.
Whether you need a one-time analysis or an ongoing partner for your data, we bring the same hands-on, detail-driven approach to every project. No generic templates, no project too small – just tools built around your specific goals.
SISTER COMPANY
When you need legal counsel alongside the numbers.
Simply Spreadsheets works in close partnership with GC Counsel PLLC, a fractional general counsel firm built specifically for contractors. Legal strategy and financial analysis regularly need to speak the same language – and on complex matters, having both capabilities coordinated from the start makes a real difference.
Whether a dispute turns on a damages calculation, a reconciliation runs into thousands of line items, or a company needs to build internal financial reporting to support growth or evaluate performance, Simply Spreadsheets brings the analytical infrastructure to match the legal work.
ABOUT GC COUNSEL PLLC
Practice focus
Construction and Procurement
Service model
Fractional General Counsel
Licensed
CO · AZ · WY*
Advisory coverage
All 50 states
Based
Denver, Colorado
“Numbers tell stories. We help you read them. With 20+ years in senior finance, from owner-operated small businesses to institutional real estate, we bring the same hands-on rigor whether you run a restaurant or a rental portfolio.”
Erin Onsager
Founder, Simply Spreadsheets
Ready to Make Your Data Work for You?
Book a free 15-minute discovery call. We’ll talk about your goals and we’ll show you exactly how we can help – no strings attached. Email simplyspreadsheets.co@gmail.com or call 860.857.8986
Simply Spreadsheets 