Blog · Retirement
Retirement Planning in a Spreadsheet: Free Excel & Google Sheets Templates You Can Steal
The exact formulas behind our retirement calculators, laid out in a spreadsheet you can download, edit, and fully understand — no black box, no account, no signup.
Retirement Planning Template
3 working sheets: savings growth, withdrawal simulation, and FIRE number. Opens in Excel or Google Sheets.
Why build this in a spreadsheet at all
Every calculator on this site — including the ones linked throughout this post — runs on formulas you can’t see. That’s fine for a quick answer, but if you want to actually understand how to calculate retirement savings balance in excel, or you want to change an assumption the calculator’s interface doesn’t expose, a spreadsheet is the more transparent tool. This one uses the identical math as our live calculators, just with every formula visible and editable.
Sheet 1: How to calculate retirement savings balance in Excel
The core formula for projecting a growing balance is the same one behind any retirement calculator excel or excel retirement calculator template worth using: each year, your balance grows by your expected return, then your annual contribution is added on top.
In the template, that’s a single formula copied down 45 rows — one per year — with each year’s ending balance feeding into the next year’s starting balance. Change the return assumption in one cell and all 45 years recalculate instantly. That’s the entire mechanism behind every “how much will I have at retirement” calculator you’ve ever used; the rest is just formatting.
| Column | Formula logic |
|---|---|
| Starting Balance | = previous year's Ending Balance |
| Annual Contribution | = Monthly Contribution × 12 |
| Growth | = (Starting + Contribution) × Return Rate |
| Ending Balance | = Starting + Contribution + Growth |
Want the same projection with a live interface instead of a spreadsheet, including the federal TSP match formula built in? See our TSP Retirement Calculator.
Sheet 2: How long will it last (the withdrawal side)
The decumulation formula is the mirror image — instead of adding a contribution each year, you subtract a withdrawal that grows with inflation:
The template’s second sheet runs this for 50 years and counts how many of them have a positive balance — that count is your answer to “how long will my money last.” It also nets out Social Security or pension income before calculating what you actually need to pull from savings, and grosses up the withdrawal correctly for taxes (dividing by (1 − tax rate), not multiplying by (1 + tax rate) — a common spreadsheet mistake that understates what you actually need to withdraw). For the same simulation with a live interface, see How Long Will My Retirement Savings Last.
Sheet 3: Your FIRE number
The simplest formula in the workbook: divide your annual retirement spending by your chosen withdrawal rate.
The sheet also includes the Coast FIRE formula — the amount you’d need invested today for compound growth alone to reach your FIRE number by a target age, with zero further contributions — plus a small sensitivity table showing your number at 4%, 3.5%, and 3.25% withdrawal rates side by side. For the interactive version with the full explanation of why that withdrawal-rate choice matters, see our FIRE & Coast FIRE Calculator.
Excel or Google Sheets — does it matter?
No. The file is a standard .xlsx, which both Excel and Google Sheets read natively. A google sheets retirement calculator or retirement calculator google sheets search usually just wants confirmation of this: upload the file to Google Drive, open it with Google Sheets, and every formula works identically — nothing in this template uses an Excel-only function.
What a spreadsheet won’t do for you
Building your own tracks exactly what you tell it to and nothing else. It won’t know that federal employees have a specific FERS annuity formula (see our FERS Retirement Calculator), that military retirement runs on four completely different systems (see our Military Retirement Calculator), or that your actual tax bill on withdrawals depends on how Social Security’s own partial-taxability formula interacts with your other income (see our Retirement Tax Calculator). A spreadsheet is the right tool once you know exactly what to model; a purpose-built calculator is faster when you don’t.
If you’re deciding between building your own tools and using ready-made ones from brand-name providers, we compared three of the most-searched options in Dave Ramsey vs. Boldin vs. Fidelity: Which Retirement Calculator Should You Actually Use?
This template is provided for educational and planning purposes only, not financial advice. It assumes a constant, smooth rate of return, which real markets never actually produce.
Frequently asked questions
Before you start editing.
Do I need Excel, or does Google Sheets work?
Either works. The file is a standard .xlsx — open it directly in Excel, or upload it to Google Drive and open it with Google Sheets. All formulas are built from functions both programs support natively.
How do I calculate my retirement savings balance in Excel from scratch?
Set up four columns: starting balance, contribution, growth, and ending balance. Each year’s ending balance formula is (starting balance + contribution) × (1 + return rate), and each new row’s starting balance references the previous row’s ending balance. Copy that down for as many years as you’re projecting.
Can I add my own rows or change the formulas?
Yes — nothing is locked. Blue text on light backgrounds marks the inputs you’re meant to change; black text is formulas. You can extend any table, add columns, or rebuild sections entirely once you understand the underlying logic.
Why would I use a spreadsheet instead of just using FinToolHub’s calculators?
Speed versus transparency. Our calculators are faster for a quick answer; a spreadsheet is better when you want to see every formula, combine multiple scenarios in one file, or build in something specific to your situation that a generic calculator doesn’t ask about.