Calculator
Savings Distribution Calculator
Savings Distribution Calculator
Ending Balance
$85,939.67
Distribution Analysis
$1,500 a month gradually draws the $250,000 down to $85,939.67 over 15 years. You take $270,000 in distributions while interest adds $105,939.67. The fund survives the full horizon with a comfortable cushion.
*Assumes a constant APY and fixed periodic withdrawals. Real savings rates vary, and this tool does not model taxes, inflation, or investment returns. Educational only, not financial advice.
How Long an Income Stream Really Lasts
Saving is only half the equation; spending it back down is the other half. A savings distribution calculator answers the decumulation question: if you start with a balance, earn interest, and draw a fixed amount every month or year, how long does the money last — and what is left at the end of your horizon? It is the mirror image of a compound-interest calculator, and for anyone living off savings (retirees, parents funding tuition, people on sabbatical), it is arguably the more important one. For American households the stakes are concrete. Median retirement account balances are far too small to support unlimited withdrawals, yet Social Security alone replaces only about 40% of pre-retirement income for an average worker. The difference has to come from savings drawn down at a sustainable rate. Withdraw too fast and the balance evaporates years before you want it to; withdraw too slowly and you leave lifestyle on the table. The arithmetic of interest versus withdrawals is not intuitive — a small change in either rate dramatically shifts the runway, which is why every serious income plan starts with this math.
Interest Accrues, Then the Withdrawal Comes Out
The simulation runs period by period. Each period the balance first earns its interest: interest = balance × (APY ÷ periods per year), using monthly compounding for monthly withdrawals and annual for annual ones. The interest is added to the balance, and then the fixed withdrawal is subtracted — never more than the balance itself. The cycle repeats for the full horizon, tracking the running balance, total withdrawn, and total interest earned. Depletion is detected the moment the balance hits zero, and the tool reports the exact period when it happened, not just the horizon's end. The relationship that drives everything is simple: if the withdrawal is smaller than one period's interest, the balance grows forever; if equal, it holds flat; if larger, it declines. But the decline is not linear — as the balance shrinks, the interest shrinks with it, so the final stretch collapses faster than the start. That accelerating tail is why 'how long will my money last' answers surprise people, and why the calculator iterates month by month rather than trusting a rough multiple.
Expert Insights
The Interest-to-Withdrawal Ratio Is the Only Rule You Need
Compare your periodic withdrawal to one period of interest on the starting balance. Withdraw less than the interest and the fund never dies; withdraw exactly the interest and it holds flat indefinitely; withdraw more and it declines. At 4% APY on $250,000, monthly interest is about $817, so a $1,500/month draw exceeds it and the fund runs down. The bigger the gap above interest, the sooner the money is gone. Compute that ratio before choosing any withdrawal amount.
The End Collapses Faster Than the Beginning
Drawdowns are deceptive: the first years look gentle because the large balance keeps throwing off interest. But as principal shrinks, interest falls too, and the same fixed withdrawal takes a bigger bite. Fund balances often survive 80% of the horizon only to vanish in the final 20%. Do not read a healthy mid-point balance as safety; the runway shortens exactly when you can least afford it.
Treat the APY as a Moving Target, Not a Constant
High-yield savings rates follow the Fed and can fall several points in a couple of years. A plan that barely survives at 4.25% APY can fail quickly at 2%. This calculator holds the rate constant for exactly that reason — to force you to choose what rate to assume. Run your plan at a conservative rate, not today's promotional one, and keep a cushion above the minimum balance you can tolerate losing.
Actionable Tips
- 1
Test Three Rates Before Trusting the Timeline
Run the same withdrawal at today's APY, at two points lower, and at zero. If the fund fails or comes dangerously close in the pessimistic cases, the withdrawal amount is too high for a plan that must work no matter what rates do. The spread between the optimistic and pessimistic runtimes tells you how much of your income plan is really a rate bet.
- 2
Ladder the Source: CDs and Treasuries for Known Expenses
If withdrawals are for known dates (tuition each September), match them with instruments that mature exactly then: a CD or Treasury ladder removes both rate risk and the temptation to sell at a bad moment. Keep the general-draw money in a high-yield account feeding this calculator's assumptions, and the dated money in a maturity-matched ladder. Separating 'must pay' from 'flexible' is what keeps the plan robust.
- 3
Review the Plan Annually and Adjust the Draw, Not the Lifestyle
Each year, re-run the calculator with the actual balance and the current APY. If the projected horizon shortened sharply, reduce next year's withdrawal modestly rather than hoping rates bail you out — early trims are cheap, late ones are painful. Conversely, if the fund is growing despite the draws, you found room for the withdrawal you actually wanted. Annual review turns a static projection into a living income plan.
Real-World Examples
Diane Discovered Her Draw Was Twice the Interest
Diane, freshly retired, had $250,000 in savings yielding 4% and planned to take $1,700 a month as her income floor. This calculator showed the $833 of monthly interest covered barely half of it, and the fund would be gone in roughly 17 years — at 78. She trimmed the draw to $1,000, supplemented the gap with a part-time consulting gig and a partial annuity, and pushed the same fund past age 90. The honest arithmetic beat the optimistic assumption.
The Okafor Ladder Paid College Without Panic
The Okafor family set aside $48,000 for their daughter's four-year public-college plan, needing $600 a month during the school years. Rather than chase the highest rate, they built a CD ladder maturing each tuition deadline and kept one semester liquid in a high-yield account they modeled here. When tuition jumped 15% freshman year, their flexible tier absorbed it without breaking the ladder. The plan's strength was not the return but the structure that matched money to dates.
Vince Learned the Tail Collapses First
Vince was funding early retirement on $500,000 at $30,000 a year with a 3.75% yield, and mid-projection the balance still looked fine at year ten. But the calculator showed the interest falling with the balance: by year fifteen the fund's last leg was collapsing, reaching zero in year eighteen — two years short of bridging to his RMD age. He picked up contract work in those final years and cut the draw by 10%, buying back six years of runway. The lesson: never assume a straight-line glide to zero.
Glossary of Terms
- Decumulation
- The phase of drawing savings down for income — the reverse of accumulation — where withdrawal rates and interest determine how long the fund lasts.
- Depletion
- The point at which a fund balance reaches zero under a fixed withdrawal schedule; the calculator reports the exact month or year it occurs.
- Annual Percentage Yield (APY)
- The effective annual interest rate a savings account pays, including compounding; the return the fund earns while it sits.
Frequently Asked Questions
Everything you need to know about this topic.
Ivy Sinclair-Wren
Financial Chaos Analyst
Ivy Sinclair-Wren is a Financial Chaos Analyst covering investing, AI, wealth psychology, and the emotional consequences of opening finance apps during market crashes. Based in Melbourne, she specializes in demystifying the US tax code and helping users navigate the intersection of spreadsheet logic and human irrationality.