How much do you actually need to retire?
Your retirement number is your real spending, minus Social Security and any pension, divided by your withdrawal rate. Not a generic 25x multiple of everything you spend. Find your real number below.
🎯 You have your number. Here's what to do with it.
Each week, one plain-English breakdown of the retirement mechanics that actually move your number: withdrawal order, Roth conversions, Social Security timing, and the bridge to Medicare. No jargon, no spam.
One email a week. Unsubscribe anytime.
Almost there.
Click the confirmation link in your inbox to finish. In the meantime, scroll down for the full plain-English explainer.
Your Retirement Number, Explained Honestly
Ask five people how much you need to retire and you'll get five different answers, most of them some version of "25 times your spending." That math is correct as far as it goes. The problem is what it's being applied to.
Step 1: The 25x Rule, Applied to the Right Number
The 25x rule comes from flipping a 4% withdrawal rate around. If a 4% withdrawal rate has historically held up over 30-year retirements, then your portfolio needs to be 25 times whatever it is you're asking it to cover each year. That part of the math is solid.
Where it goes wrong is when people apply the multiple to their entire annual spending, as if Social Security didn't exist. For most retirees it covers a real share of the bill. Skipping that step is the single biggest reason people believe they need far more than they actually do.
Step 2: Pick a Withdrawal Rate You're Comfortable With
4% is the common default, drawn from historical research into how often a 30-year retirement survived different withdrawal rates. It's not a law of physics. A more conservative 3% to 3.5% lowers your odds of running out, but raises your target number. A more aggressive 5% lowers the target but takes on more risk, particularly if a downturn hits in the first few years of retirement, a problem known as sequence-of-returns risk.
There's no universally correct choice. It's a trade-off between how much you save now and how much risk you're willing to carry later.
Step 3: Check Whether You're On Track
Knowing your number only matters if you can tell whether your current savings rate gets you there. The calculator above grows your current investments and monthly contributions forward at your expected after-inflation return, and compares the result at your target retirement age against your retirement number. If the projection falls short, the gap is something you can act on now, by saving more, adjusting your spending target, or pushing your retirement age back a few years, each of which moves the math meaningfully.
| Annual spending | Guaranteed income | Portfolio gap | Retirement number (4%) |
|---|---|---|---|
| $50,000 | $20,000 | $30,000 | $750,000 |
| $70,000 | $24,000 | $46,000 | $1,150,000 |
| $90,000 | $28,000 | $62,000 | $1,550,000 |
| $120,000 | $32,000 | $88,000 | $2,200,000 |
Notice how much the guaranteed-income column changes the result. A retiree who ignores it entirely overshoots every one of these targets by a wide margin, which can mean working years longer than actually necessary.
What This Calculator Does Not Cover
It assumes a steady return. Real markets don't deliver the same return every year. A weak stretch early in retirement is far more damaging than the same weak stretch later, which is why it's worth rechecking your number periodically rather than setting it once.
Social Security estimates can change. Your actual benefit depends on your earnings history and the age you claim it. Claiming earlier than your full retirement age permanently reduces it; waiting past it increases it. Check your real estimate at ssa.gov rather than guessing.
It's before taxes. Withdrawals from a traditional 401(k) or IRA are taxable income; Roth withdrawals generally aren't. Which accounts you draw from, and in what order, changes your real after-tax number. That's exactly what the withdrawal order guide covers.
Healthcare before Medicare isn't modeled here. If you retire before 65, you're covering health insurance yourself until Medicare starts. That's a real, often-underestimated cost covered in the bridge to 65 guide.
How This Calculator Works
It runs three steps. First, it subtracts your guaranteed income from your annual spending to find the gap your portfolio actually has to cover, then divides that gap by your withdrawal rate to get your retirement number. Second, for comparison, it shows the naive result of applying the same withdrawal rate to your full spending with no guaranteed income subtracted. Third, it grows your current investments and monthly contributions forward, month by month, at your expected after-inflation return, and compares the projected balance at your target retirement age against your retirement number. Everything is in today's dollars and before taxes, which depend on your account types and aren't modeled here.
Educational purposes only. This calculator illustrates the mathematics of retirement planning based on the inputs you provide. It does not constitute financial, tax, or legal advice, or a personalized recommendation. Projections are hypothetical and assume a constant annual return, which real markets do not deliver. The 4% rule is a historical guideline, not a guarantee, and sequence-of-returns risk can change outcomes. Results exclude taxes and are shown in today's dollars. Retire BFF is not a registered investment advisor. Always do your own research and consider consulting a qualified financial professional before making retirement decisions.