Savings Rate Calculator
Your savings rate is the single most powerful lever in your FIRE journey. Enter your income and expenses to see your current savings rate, your FIRE number, and exactly how many years until financial independence — plus a full table showing how each 10% increase in savings rate cuts years off your timeline.
Enter your income and expenses — results update instantly as you type:
Annual gross income
Enter your total annual income before taxes. This field is informational and used to give context alongside your take-home pay. If you are self-employed, enter your gross business revenue before expenses.
Annual take-home income
Enter what actually hits your bank account after all taxes and deductions. This is the income you live on and save from. For most salaried employees, this is your net pay multiplied by your pay periods per year.
Annual expenses
How much do you spend in a year? Include housing, food, transport, subscriptions, travel, and discretionary spending. This drives both your savings rate calculation and your FIRE number. Lower expenses have a double impact: they increase your savings AND lower your target.
Expected annual return
Adjust the slider for your assumed investment return rate. A diversified stock portfolio has historically returned 7–10% nominally. Use 5–7% for conservative estimates. The default is 5% to produce realistic results for most scenarios.
Current portfolio value
Enter the current value of all your invested assets: 401(k), IRA, Roth, brokerage accounts. A non-zero starting portfolio reduces your years to FI by letting compound growth work from day one. Enter 0 if you are starting from scratch.
Savings Rate (%)
The percentage of your take-home income you save and invest each year. This is the primary variable that determines how quickly you reach FI. A 50% savings rate means you can theoretically retire in about 17 years from scratch at a 5% return.
Annual Savings
The dollar amount you save per year: take-home income minus annual expenses. This is the fuel for your wealth-building engine. Even small increases in annual savings compound dramatically over time.
FIRE Number
The portfolio size needed to sustain your expenses indefinitely using the 4% safe withdrawal rate. It equals your annual expenses multiplied by 25. Reducing expenses shrinks this target — one of the most powerful moves in the FIRE playbook.
Years to FI
How many years at your current savings rate and return assumption before your portfolio reaches your FIRE number. This uses the Mr. Money Mustache formula, which accounts for compound growth on your existing portfolio and ongoing contributions.
Years to FI Table
The table rows show years to FI at savings rates from 10% to 90% — holding your take-home income and return constant. The row closest to your current savings rate is highlighted. Use this to model the impact of increasing your savings rate.
The calculator uses three formulas in sequence. First it calculates your savings rate, then your FIRE number, then the years to FI using the logarithmic compound growth formula popularized by Mr. Money Mustache.
Savings Rate = (Take-Home − Expenses) ÷ Take-Home
Example: ($60,000 − $45,000) ÷ $60,000 = 25%
FIRE Number = Annual Expenses ÷ 0.04
Example: $45,000 ÷ 0.04 = $1,125,000
The years to FI formula accounts for the compound growth of both your existing portfolio and your ongoing annual savings contributions:
Years = log((F × r + S) ÷ (P × r + S)) ÷ log(1 + r)
F = FIRE Number · r = annual return · S = annual savings · P = current portfolio
If your return rate is zero, a simpler linear formula is used: (FIRE Number − Portfolio) ÷ Annual Savings. If your savings rate is negative (expenses exceed income), years to FI is shown as 100+ to indicate FI cannot be reached at the current trajectory.
Why savings rate beats income
Two households earning the same income can have radically different timelines to FI. A household spending 80% of income needs 45 years to retire; one spending 50% needs only 17. Income matters less than what you keep.
The double benefit of lower expenses
Reducing annual expenses improves your savings rate AND reduces your FIRE number. Cutting $5,000 per year increases your annual savings by $5,000 and reduces your FIRE target by $125,000 (25×). No other single move has this dual impact.
Compound growth on existing savings
The formula gives full credit to your existing portfolio — it grows at your assumed return rate, reducing the heavy lifting your annual savings must do. Even a modest portfolio of $50,000 can meaningfully compress your timeline.
The 4% rule assumption
The FIRE Number uses the 4% rule: annual expenses ÷ 0.04 = 25× expenses. This is based on the Trinity Study, which found that a 4% initial withdrawal rate sustained a 30-year retirement in the vast majority of historical periods.
Average American — 15% savings rate
Serious saver — 40% savings rate
FIRE optimized — 65% savings rate
Notice how dramatically the FIRE Number drops as expenses fall. The 65% saver not only contributes more each year — they also need far less to retire. This dual compression is why FIRE practitioners focus on expenses first and income second. Cutting expenses is the highest-leverage move available.
In 2013, Mr. Money Mustache published a blog post titled The Shockingly Simple Math Behind Early Retirement. The central insight: your savings rate — not your income, not your investment picks — is the primary determinant of how long you must work.
A person saving 10% of income needs roughly 43 years to retire (at 5% return). A person saving 50% needs only about 17 years. A person saving 75% can retire in about 7 years. The relationship is non-linear: each additional percentage point of savings rate has a larger impact than the last.
This insight is liberating because it decouples retirement from income. A household earning $60,000 and saving 50% will reach FI before a household earning $150,000 and saving 10%. What matters is the gap between what you earn and what you spend.
Savings rate vs. investment returns
For most people in the accumulation phase, savings rate has a far larger impact on timeline than investment returns. Increasing savings from 20% to 30% cuts years off your timeline more reliably than chasing higher returns.
The frugality multiplier
Every dollar you don't spend does double duty: it increases your savings by $1, and it reduces your FIRE number by $25 (since the FIRE number is 25× annual expenses). This is why FIRE practitioners describe frugality as a superpower.
Starting point matters less than you think
Whether you're starting from $0 or $100,000, the savings rate formula shows that your ongoing savings rate dominates your timeline. A late starter with a high savings rate can still reach FI faster than an early starter with a low one.
Benchmarks to aim for
Financial advisors typically recommend saving 10–15% of income. FIRE practitioners target 40–70%+. Even moving from 15% to 25% can cut your working years significantly — use the calculator's table to model the impact of each 10% increase.
Your savings rate is the percentage of your take-home income that you save and invest each year. It is calculated as: (Take-Home Income − Annual Expenses) ÷ Take-Home Income. A 25% savings rate means you invest $1 for every $3 you spend.
Traditional financial advice targets 10–15%. FIRE practitioners typically aim for 40–70% or more. At 50%, you can theoretically retire in about 17 years from scratch (at a 5% return). At 65%, closer to 10 years. There is no single 'right' number — it depends on your income, expenses, lifestyle goals, and timeline.
This calculator uses take-home income (after taxes) for the savings rate formula, which is the most practical approach. Your savings rate is about what you do with money you actually control. Some FIRE resources use gross income — just be consistent with whatever definition you track over time.
The inputs are in today's dollars. The expected annual return you enter is a nominal return. If you want to model real (inflation-adjusted) returns, reduce your return rate by your expected inflation rate — for example, enter 5% instead of 7% if you expect 2% inflation. The FIRE Number via the 4% rule is designed for inflation-adjusted withdrawals, so using a slightly conservative return rate is appropriate.
The FIRE Number is the portfolio size from which you can withdraw your annual expenses indefinitely using the 4% safe withdrawal rate. At 4% withdrawal, your portfolio needs to be 1 ÷ 0.04 = 25 times your annual spending. This is based on the Trinity Study, which found a 4% initial withdrawal rate survived the vast majority of 30-year historical periods.
If your savings rate is very low (or negative), the formula can produce very large numbers or infinity — meaning at that savings rate, you would never mathematically reach FI. Rather than showing 'infinite years', the table caps at 100 to indicate that a given savings rate is not a viable path to financial independence within a realistic timeframe.
Yes — your 401(k), IRA, Roth IRA, and all other investment contributions count. The key distinction is the difference between your take-home income and total spending. If you contribute to a 401(k) before your paycheck hits your bank, your take-home is already reduced, so just use your actual after-all-contributions net income as take-home and your actual spending as expenses.
Employer matching is effectively part of your total compensation. Some people include it in their savings rate calculation; others exclude it for a conservative estimate. Either is fine — consistency over time matters more than the exact methodology. Including the match gives a higher, more optimistic savings rate; excluding it gives a more conservative baseline.
Get your full FIRE projection
See your complete timeline to retirement with income, expenses, contributions, and projected FIRE age all in one place.
Project your investment growth
See exactly how your investments compound over time with regular contributions — and how starting earlier changes everything.
Disclaimer: This calculator is for educational and informational purposes only. It does not constitute financial, investment, or tax advice. All projections are estimates based on hypothetical scenarios — actual investment returns vary and past performance does not guarantee future results. The years-to-FI calculation assumes constant annual returns and contributions, which does not reflect real-world market volatility or life changes. The 4% safe withdrawal rate is a historical guideline, not a guarantee. Consult a qualified financial advisor before making investment decisions.