Can I Retire? Series — Part 7 of 12
We’ve spent six posts building up to this moment.
You know what you spend. You’ve accounted for big rocks. You’ve adjusted for what changes in retirement. You’ve identified your investable assets and sorted them into buckets. You’ve tallied up your guaranteed income.
Now we put it together.
The Gap = Your Retirement Spending − Your Guaranteed Income
This is the number that actually matters. This is what your portfolio has to produce, year after year, for as long as you live. Everything else in retirement planning — withdrawal rates, asset allocation, tax strategy — is in service of filling this gap.
The Simple Math
Let’s make this concrete.
Example 1: You need $80,000/year in retirement. Social Security will provide $35,000 (combined for you and spouse). You have a small pension of $10,000. Your guaranteed income is $45,000. Your gap is $35,000.
Example 2: You need $100,000/year. Social Security provides $28,000. No pension. Your gap is $72,000.
Example 3: You need $60,000/year. Social Security provides $40,000. Pension provides $25,000. Your guaranteed income exceeds your spending. Your gap is zero — or negative. Your portfolio is gravy.
Same spending, wildly different situations. The gap is what separates “can I retire?” from “when can I retire?” from “I could have retired years ago.”
Why the Gap Is the Real Target
Most retirement advice focuses on total savings. “You need $1 million to retire.” “You need 25 times your income.” “You need $2 million to be safe.”
These rules of thumb are mostly useless because they ignore the gap.
Someone with a $35,000 gap needs far less than someone with a $72,000 gap. Someone with a zero gap might not need any portfolio at all (though having one provides cushion and flexibility).
The gap is personal. It’s specific to your spending, your income sources, and your timing. Generic advice can’t capture it. Only your numbers can.
The Gap Changes Over Time
Here’s where it gets more interesting — and more complicated.
Your gap isn’t fixed. It shifts as income sources turn on and off.
Early retirement (before Social Security): If you retire at 58 but don’t claim Social Security until 67, you have nine years where your portfolio covers everything. Your gap equals your full spending. This is the most demanding phase.
Middle retirement (Social Security active): Once Social Security kicks in, your gap shrinks substantially. The pressure on your portfolio drops.
Late retirement (spending shifts): As discussed in Part 3, spending often declines in your 70s (less travel, fewer activities) then may rise again in your 80s (healthcare costs). Your gap fluctuates.
A good retirement plan doesn’t assume a single gap — it models the gap over time.
An Example Timeline
Let’s say you’re 58, planning to retire now, claim Social Security at 67, and expect to live to 90.
Ages 58-66 (9 years): You need $75,000/year. No Social Security yet. Gap = $75,000. Portfolio covers everything.
Ages 67-90 (23 years): Social Security starts at $32,000/year. Gap = $43,000. Portfolio supplements.
Over 32 years, your portfolio needs to produce $75,000 × 9 = $675,000 in the first phase, then $43,000 × 23 = $989,000 in the second phase. That’s $1.66 million in total withdrawals — but not all at once. The timing and sequence matter enormously.
This is why simple “multiply by 25” rules fall short. Your gap has phases.
How the Calculator Handles This
The caniretire.app calculator models this year by year.
It takes your spending and subtracts your guaranteed income to find the gap. It withdraws from your portfolio to fill that gap — pulling from the appropriate buckets based on your withdrawal sequence. It accounts for taxes on those withdrawals. It applies market returns (from real historical data). It adjusts for inflation. It runs this simulation across thousands of paths.
The result isn’t a single number — it’s a probability. Given your gap, your assets, and historical market behavior, here’s how often your money lasts.
A small gap with modest assets might have the same success rate as a large gap with substantial assets. The gap and the portfolio are two sides of the same equation.
Shrinking the Gap vs. Growing the Portfolio
If your success rate isn’t where you want it, you have two levers:
Grow your portfolio. Work longer, save more, invest better. This is what most people focus on.
Shrink your gap. Reduce spending, delay Social Security (to get a higher benefit), move somewhere cheaper, find additional income. This is often faster and more certain.
Every $1,000 you reduce your gap is roughly $25,000 less you need in your portfolio (using the 4% rule as a rough guide). Cut $5,000 from your annual spending? That’s like having $125,000 more saved.
Delaying Social Security from 62 to 70 might add $15,000/year to your benefit. That’s like having $375,000 more in your portfolio — except it’s guaranteed income, not market-dependent.
The gap gives you a lever most people ignore.
Your Homework
Calculate your gap.
Take your retirement spending number (from Parts 1-3). Subtract your guaranteed income (from Part 6). That’s your gap.
If your guaranteed income doesn’t start immediately at retirement, calculate two gaps: the early-phase gap (full spending, no Social Security) and the later-phase gap (after income kicks in).
Write these numbers down. You now have the core inputs for the calculator: your spending, your assets (by bucket), your guaranteed income, and your gap.
In Part 8, we’ll tackle withdrawal sequencing — the order you pull from your buckets. It’s more important than most people realize, and getting it right can add years to your portfolio’s life.
Next: Part 8 — Withdrawal Sequencing
