Understanding Your Results

RetireRange doesn’t give you one number — it gives you a distribution of outcomes across thousands of simulated futures. That’s the point: your real future is unknowable, so the honest answer is a range and a probability, not a single prediction. This page explains how to read what you see and, more importantly, how to act on it.

Start with three numbers

After a run, look at these first.

Success Rate

The share of simulated futures in which your money lasted to the end of your plan. 90% means your plan survived in 9 of 10 simulated futures.

The catch most people miss: higher isn’t automatically better. A 99% success rate can mean you’re being so cautious that you’ll leave a large unspent balance and live smaller than you needed to. Think of success rate as resilience — aim for a level you’re comfortable with (many people target 85–95%), not the maximum. If yours is very high, ask the opposite question: could I spend more?

Income Gap Rate (shortfall)

Shown as "Income Gap Rate" on the Results tab.
The share of futures where, at some point, you couldn’t fully fund your spending target even after drawing from every account. For many retirees this matters as much as the success rate — it measures how often you’d have had to cut back, even briefly.

The range itself (the trajectory chart)

The shaded bands show how your portfolio could evolve over time:

• Center line — the median (typical) outcome.
• Inner band — the middle half of outcomes (25th–75th percentile).
• Outer band — the broader range (10th–90th), i.e. unlucky to lucky.

A wide band means more uncertainty (often a stock-heavy plan). A band that trends toward zero in its lower edge is a warning. Toggle nominal vs. real dollars to see whether your income holds its purchasing power over time — real dollars are usually the more realistic view.

Watch the bottom of the range, not just the middle. The median assumes average luck. Your plan’s safety lives in the P10 (worst-luck) line — if that holds up, you’re robust; if it collapses, you’re exposed even if the median looks fine.

What your plan leaves behind

• Median ending balance — the typical amount left at your plan’s end; a proxy for your legacy.
• After-tax legacy — what your heirs would actually keep after the tax on what they inherit, applied per account type: inherited Traditional and HSA balances are taxed at your heirs’ ordinary income rate (plus any state rate), while Roth, Taxable, and VEBA pass at full value (Taxable via a step-up in basis). This is the more realistic legacy number — and the one to use when comparing a Roth-heavy plan against a Traditional-heavy one. Set the rates on the Assumptions tab; see Taxes.

The deeper charts

When you want detail beyond the headlines:

• Ruin-probability chart — the cumulative share of futures that have run out of money by each point in time. This is where you learn when failures happen — something Success Rate alone can’t tell you. Success Rate answers "did the plan ever fail?"; it can’t distinguish a plan whose failures cluster at year 35 (you outlived a long, mostly-funded retirement by a few years) from one whose failures hit at year 12 (an early sequence-of-returns disaster). Both can read "90%," but they’re completely different risks. So read the shape: a curve that stays flat and near zero until very late is reassuring, while one that ramps up steeply in the first several years is a sequence-of-returns warning — failures are early and catastrophic. Flat-and-late beats steep-and-early, even at the same success rate.
• Monthly income — your income over time, split into general spending, medical, and Social Security.
• Tax summary — estimated yearly tax; useful for spotting spikes from large RMDs or conversions.
• RMD projection — when and how much you’ll be forced to withdraw from Traditional accounts.
• Ending-balance distribution — the spread of final outcomes; a long right tail means big-legacy futures, a pile-up near zero means many near-depletions.
• Account stack — how each account draws down over time and which type carries you at each stage.

Stress-testing the result

The percentile bands capture general bad luck. To pressure-test against specific bad histories:

• Bad-sequence overlay (a button on the Results tab) drops your plan onto the worst real starting points on record (1929, 1966, 2000, 2008).
• The Historical backtest replays your plan across every start year since 1928.

See what if returns disappoint? for how to use these together.

Turning results into decisions

A single run is a starting point, not a verdict. The real workflow:

1. Save it as a scenario.
2. Change one thing and run again.
3. Compare them on the same market sequences.

If your success rate is lower than you’d like: delay retirement, trim or phase spending, delay Social Security, switch to Guardrails, or hold a larger cash reserve (optionally with recovery refill, so it restocks in good years). If it’s very high: consider spending more, retiring earlier, or gifting — you may have more room than fear suggests.

One caution on the "Lifetime Taxes Paid" figure (shown in the Compare tab and Optimizer): never minimize it on its own. At high withdrawal rates taxes can drop simply because the portfolio depletes faster — fewer dollars left to tax. Always find the high-success-rate plans first, then compare taxes within that group.

Unfamiliar with a term? See the Glossary.