Retirement Income Gap Calculator
Compare your expected retirement expenses with your guaranteed income and see how much your savings need to cover.
Today's dollars. The Budget Builder can help you total this.
Annuities, rental income you count on, part-time work.
Your gap
Monthly gap your savings must fill
$3,200
Guaranteed income covers $2,800 of your $6,000 monthly expenses. Filling the rest at a 4% withdrawal rate takes about $960,000 of savings.
Short in this scenario
Where your monthly income could come from
View data table
| Category | Amount | Share |
|---|---|---|
| Social Security | $2,800/mo | 47% |
| Savings at 4% | $1,167/mo | 19% |
| Uncovered | $2,033/mo | 34% |
- Guaranteed monthly income
- $2,800
- Savings needed to close gap (4%)
- $960,000
- Your current savings
- $350,000
- Additional savings needed
- $610,000
What this may mean for you
A rule of thumb hiding in this math: every $100/month of expenses needs about $30,000 of savings at a 4% withdrawal rate. Shrinking the gap — by trimming expenses or delaying Social Security for a larger check — moves the savings target dramatically.
Results are estimates for educational purposes and may not reflect your complete financial or tax situation.
Understanding this calculator
Retirement income planning starts with a simple subtraction: monthly expenses minus guaranteed monthly income. Whatever is left over is the gap your savings must fill, month after month, for as long as retirement lasts.
Once you can see the gap, you can work it from both ends — trim the expense side, or grow the income side by delaying Social Security, working part-time for a while, or saving more before you retire. Small monthly changes translate into surprisingly large changes in the savings you need, because every monthly dollar of gap requires roughly 300 dollars of savings at a 4% withdrawal rate.
Assumptions and methodology
- Gap = monthly expenses − (Social Security + pension + other guaranteed income).
- Savings needed = annual gap ÷ the withdrawal rate you select (e.g., a $1,000/mo gap at 4% implies $300,000). Withdrawal rates are planning guidelines, not guarantees.
- The coverage meter shows guaranteed income plus what your current savings could contribute at the same withdrawal rate.
- Everything is in today's dollars; taxes are not modeled.
Last reviewed August 30, 2026. Year-specific figures show their tax or data year in the tool; data is reviewed when the IRS, SSA, and CMS publish annual updates.
Common questions
What withdrawal rate should I use?
4% is a common starting point for a roughly 30-year retirement, but it's a guideline, not a guarantee. The scenario tabs let you see 3.5% and 4.5% too.
My gap is negative — what does that mean?
Your guaranteed income more than covers your expected expenses. Savings then become flexibility money — travel, gifts, healthcare surprises — rather than the grocery budget.
Keep going
- Retirement IncomeSee how much monthly income your savings could support in retirement, and how it compares with what you plan to spend.Calculator
- Social Security TimingCompare claiming at every age from 62 to 70 and see monthly amounts, lifetime totals, and break-even ages.Calculator
- How Long Will Savings Last?See how long your savings could last at a given monthly withdrawal, with inflation and returns included.Calculator
- The Retirement Income ChecklistTurn a pile of accounts into a monthly paycheck — one step at a time.Guide
- What the 4% Rule Actually Says — and What It Never Promised6 min readArticle
- The First Year of Retirement: What Actually Surprises People6 min readArticle
Want a second set of eyes on this?
If you'd like to talk through what these numbers mean for your situation, you can schedule a free, no-pressure conversation. No products, no pitch — just questions answered.