The engine behind the next-dollar order.
Next Dollar does more than show a generic flowchart. It normalizes your answers, calculates contribution room, ranks each dollar, models tax drag and growth, then turns the plan into a workbook you can keep.
Answers become planning inputs
Income, savings capacity, cash, debt, filing status, account access, employer benefits, and current contributions are normalized into one planning state.
The router fills priorities
Monthly capacity moves through the priority order, stopping each step when its target, balance, or annual contribution room is reached.
The forecast compares paths
Pre-tax, Roth, HSA, employer-match, taxable, and cash dollars keep their different tax and growth treatment.
The plan becomes usable
The ranked order becomes monthly targets, forecast controls, setup tasks, and a workbook with yearly tabs.
- Data entry
- Typed by you
- Account access
- No linking
- Output
- Educational estimate
- Limit year
- 2026
Plan access
What the $12 unlock includes
Your first ranked move and why it comes first.
Every remaining move, monthly targets, adjustable forecast, and workbook.
Pipeline
How an answer becomes a plan
Read
Capture typed answers; no bank, brokerage, retirement, or other account logins are required.
Normalize
Convert entered amounts into income, monthly capacity, APR-based debt tiers, cash coverage, and account eligibility.
Route
Allocate the next dollar through match, safety, debt, tax accounts, and overflow until the monthly capacity is used.
Output
Generate the free first move, locked remaining steps, forecast controls, checklist, and tracker workbook.
Priority router
How the next dollar is ranked
Employee contribution needed to capture the full match is calculated first, then spread across the months left in the year.
Cash savings divided by monthly expenses determines coverage; the plan tops up the selected emergency-fund target without overfilling it.
Entered balances, actual APR ranges, and required minimums determine whether payoff is high, medium, or low priority and cap extra payments at the balance.
HSA, IRA, 401(k), backdoor Roth, and mega-backdoor room are ranked only when the answers make them relevant.
529, regular brokerage, and low-rate debt are placed after capped higher-priority moves are handled.
Core calculations
The math that runs under the UI
The router does not just list accounts. It allocates the amount you said you can save each month, then subtracts each funded step.
Cash coverage determines whether the plan is in critical, low, stable, or high liquidity mode, then caps the emergency-fund top-up at the remaining gap.
The model separates employee deferrals from employer dollars so match capture and mega-backdoor room do not get mixed together.
Starting in July is not treated like starting in January. Remaining annual room is spread across the months left in the year.
The forecast does not pretend taxable investing compounds tax-free. Dividends, interest, realized gains, and final unrealized gains are modeled separately.
Recurring contributions can grow year by year, so the long-term view is not locked to today's monthly dollar amount forever.
Limit engine
The account limits the model checks
plus catch-up where age applies
used in mega-backdoor room
per person before catch-up
self-only or family coverage
The model also checks Roth IRA income phaseouts, Traditional IRA deduction phaseouts, HSA coverage tier, age catch-ups, spouse workplace-plan answers, and projected future-year limits for tracker tabs.
Forecast model
How the growth projection is different from a simple calculator
- Customized plan after taxes
- Same monthly dollars in taxable brokerage
- Cash / savings baseline after tax
- Total contributions, so growth is not confused with principal
Tracker
How the paid workbook is generated
Privacy and limits
What Next Dollar does not do
You do not link a brokerage, 401(k), IRA, HSA, or bank account. You type the numbers you want the model to use. The app can save progress and unlock state in this browser. Share links and checkout return links can reopen a plan. Checkout recovery stores an encrypted plan payload with Stripe and uses the paid session link as an access key, so only share full plan or re-access links with people you trust.
Next Dollar is not a registered investment adviser, broker-dealer, tax-preparation service, or fiduciary. It does not manage accounts, move money, prepare tax returns, or review your full situation.
Disclosures
Important limits before acting
Any tickers or fund categories shown are illustrative examples of common low-cost fund categories. They are not recommendations to buy or sell a specific security. Comparable options exist at many providers.
Account limits, tax rules, phaseouts, employer-plan features, market returns, and state rules can change. The model simplifies real-world rules and uses assumptions where complete tax-law or plan details are not entered.
The current product is built for United States personal-finance and federal tax rules. It is not suitable for non-U.S. tax systems, and complex business, equity-compensation, estate, or cross-border situations require separate review.
Markets are uncertain. Actual returns can be negative and may differ materially from modeled assumptions. Projections are educational estimates, not guarantees.
Before making a real investment, contribution, conversion, payoff, or tax decision, consider reviewing the details with a qualified fiduciary adviser, CPA, attorney, or benefits professional who can evaluate your full circumstances.