Savings Rate Calculator
The single most powerful number in FIRE: what your savings rate does to your timeline.
Your numbers
Assumptions
Your savings rate
36.8%
Saving $35,000 a year, you reach financial independence in 19 years 7 months — around age 52.
- Saved each year
- $35,000
- Your FIRE number
- $1,500,000
- Real return
- 5.37%
General information, not advice
Years to independence, by savings rate
Starting from what you already have invested. This is the chart that convinces people the savings rate matters more than the return.
- 5%46.3 yrs
- 10%39.3 yrs
- 15%34.0 yrs
- 20%29.8 yrs
- 25%26.3 yrs
- 30%23.2 yrs
- 35%20.5 yrs
- 40%18.1 yrs
- 45%15.9 yrs
- 50%13.8 yrs
- 55%11.9 yrs
- 60%10.2 yrs
- 65%8.5 yrs
- 70%6.9 yrs
- 75%5.4 yrs
- 80%4.0 yrs
Why the savings rate dominates
Every dollar you stop spending does two jobs. It becomes a dollar invested, and it permanently lowers the portfolio you need, because your target is your spending divided by your withdrawal rate. Cut $1,000 of annual spending at a 4% withdrawal rate and your FIRE number drops by $25,000 — before you have invested a cent of it.
That compounding of both sides is why the table above bends so sharply. Going from a 10% to a 20% savings rate buys you far more than a percentage point of extra return ever will, and it is entirely within your control.
Once you know roughly where you sit, the full FIRE calculator adds the parts this one deliberately leaves out: tax, employer contributions, and whether you can actually reach your money before preservation age.
Assumptions and limitations
Every result above rests on these assumptions, and each can be changed in the inputs. Why the defaults are reasonable
- Return
- 8.0% a year
- Inflation
- 2.5% a year
- Withdrawal rate
- 4.0%
Limitations
- Spending stays the same in retirement. If you plan to spend more or less once retired, the years shown will be too few or too many.
- One steady return, with no fees or tax. Fees and tax slow growth. Enter a return after both to allow for them, or the years shown will be too few.
- All of your savings are reachable. Money in super or a 401(k) is locked until preservation age, so retiring earlier needs savings outside it. The FIRE calculator tests that.
Why the savings rate matters more than income
Your savings rate is the share of take-home pay you invest. It decides how long financial independence takes more than any other number, because it works twice. A higher rate puts more into investments each year, and it also means you live on less, so the portfolio you are aiming for is smaller.
That is why two people on very different incomes with the same savings rate reach independence in roughly the same number of years, starting from nothing. Income sets how comfortable the journey is; the savings rate sets how long it takes.
Years to financial independence by savings rate
| Savings rate | Years to FI |
|---|---|
| 10% | 49 years |
| 20% | 35 years |
| 30% | 27 years |
| 40% | 21 years |
| 50% | 16 years |
| 60% | 12 years |
| 70% | 9 years |
The curve is steep at the low end and flattens at the high end. Going from 10% to 20% saves decades; going from 60% to 70% saves a few years. Money you already have invested shortens every figure in the table, which is what the tool's "Already invested" input does.
The maths behind the tool
The tool assumes you will spend in retirement what you spend now. Your FIRE number is that spending divided by your withdrawal rate. Each year, your savings are added at the end of the year and the whole portfolio grows at the real return: your expected return less inflation, so everything stays in today's dollars. The answer is the number of years until the portfolio reaches the FIRE number.
It is closed-form maths, deliberately simple so you can check it by hand. With the default 8% return and 2.5% inflation, the real return is about 5.4%.
An example
The tool opens with an example: take-home pay of $95,000, spending of $60,000, a savings rate of 36.8%, and $120,000 already invested. The FIRE number is $1,500,000, and at a 5.4% real return it takes about 20 years, so a 32-year-old would get there at around 52.
Spending $5,000 a year less lifts the savings rate to 42.1% and cuts the time to about 17 years. Two things happen at once: $5,000 more is invested every year, and the FIRE number falls by $125,000.
The table and the example both assume you will spend in retirement what you spend now. If a mortgage will be paid off or children will leave home, retirement spending may be lower and the real timeline shorter; if you plan to travel more, longer. A more cautious withdrawal rate, such as 3.5%, raises the FIRE number and adds a few years to every figure.
Measuring your own savings rate
The tool uses take-home pay: what reaches your bank account after income tax and payroll deductions. Savings are take-home pay less spending. Two things are worth deciding consistently:
- Retirement contributions taken from your pay before it arrives, such as Australian salary sacrifice or a US 401(k) deferral, are savings too. Adding them to both take-home pay and savings gives a truer rate.
- Employer contributions, such as the Australian Super Guarantee or a US 401(k) match, are extra savings you never see. Including them makes your rate look higher; leaving them out is more conservative.
- Mortgage principal builds equity but does not fund retirement spending unless you plan to sell. Most people count it as spending for this purpose.
What the tool leaves out
It does not know which country you live in. It ignores tax in retirement, the age at which retirement accounts unlock, government pensions and the order of returns. Those can move the answer by years, which is why the full calculators exist: the Australian FIRE calculator and the US FIRE calculator model your pay, tax, super or 401(k), and the bridge to preservation age, year by year.
Frequently asked questions
What is a good savings rate for FIRE?
There is no single figure; it depends on how soon you want to stop. As the table shows, from a standing start at the default return, 50% of take-home pay reaches independence in about 16 years, while 20% takes about 35.
Does the tool use gross or take-home pay?
Take-home pay, after tax. Pre-tax retirement contributions can be added to both take-home pay and savings if you want them counted.
Does a higher income help if my savings rate stays the same?
Not to the timeline. Starting from nothing, the same savings rate takes about the same number of years at any income, because a bigger income usually comes with bigger spending and a bigger FIRE number. A raise shortens the timeline only to the extent that it lifts the savings rate.
Why does spending less shorten the time so much?
Because it raises your savings and lowers your FIRE number at the same time. Every dollar of spending you cut is a dollar more invested and about 25 dollars less to accumulate at a 4% withdrawal rate.