How it works
Explore how allocation and recurring contributions affect a hypothetical USD portfolio. Separate price changes, income, withdrawals and purchasing power over 1–50 years.
Each month: allocate beginning contributions, apply price changes, accrue income on opening holdings, pay on the chosen hypothetical schedule, reinvest or withdraw net income, deduct additional fees, allocate ending contributions, optionally rebalance annually, then record the ledger. Unpaid income is a separate receivable included in value.
Monthly price factor = (1 + annual price change)^(1/12). Income generated = opening holdings × annual income yield / 12.
Closing value = opening value + contributions + price gain + gross income − withdrawals − taxes − extra fees. Reinvestment moves receivables into holdings without creating new income.
Real value = nominal value / accumulated inflation factor. Economic gain = invested value + net withdrawals − contributed principal.
Verified worked example
Verified illustration: $1,200 initial capital, no contributions or price changes, 12% annual income-rate assumption paid monthly and withdrawn, no fees or taxes. Each month generates $12; after one year invested value remains $1,200, withdrawn income is $144 and economic gain is $144. At 0% inflation, real invested value is $1,200. This is arithmetic, not a suggested yield.
Interpretation and limits
Illustrative projections are not personalized investment advice or guaranteed outcomes. Distributions may change or stop; constant current yields cannot predict long-term returns.
Asset-class approximation only: no exact bill maturities, bond coupons or security-specific TIPS indexation. Treasury ETFs can differ from individual Treasuries held to maturity. A real TIPS yield is not nominal cash income; CPI is not added automatically to NAV.
Bond funds can lose value when rates rise. Government money market funds are investment funds, not bank deposits, and are not automatically FDIC insured.
No live quotes, named-fund recommendations, Monte Carlo probabilities, capital-gains tax or broker-specific transaction fees. Tax drag is a hypothetical haircut on paid income only, not tax advice.
Bounds: initial investment up to $100 million; monthly contributions up to $1 million; 1–50 years; projected nominal or real value up to $1 trillion. Empty or invalid values block results. Yield means income rate; reinvestment retains paid income; nominal dollars are future dollars, while real dollars express today’s purchasing power.
Assumptions & sources
All future rates are editable illustrative assumptions held constant. USD does not imply U.S. tax residency. Inputs stay in browser memory. Net fund assumptions already include embedded fund expenses.
Invested value includes separately disclosed unpaid income. Withdrawals leave invested assets; future rates are held constant.
- Treasury rates — U.S. Treasury
- Treasury pricing — TreasuryDirect
- CPI — BLS
- Money market funds — SEC Investor.gov
Method verified2026-10-31. Treasury observation2026-10-30; CPI period September2026. Official websites may restrict access by network or location; US accessibility was not verified.
FAQs
Is the income shown a monthly payment?
Monthly equivalent income divides an assumed annual income rate by twelve using terminal holdings. Scheduled payments appear separately and use your explicitly hypothetical 1, 3, 6 or 12-month interval. Neither is guaranteed.
How are dividends kept separate from total return?
The model uses price change excluding distributions plus a separate income yield. There is no total-return input to which dividends are added. Fund assumptions are net of embedded expenses; only additional costs are deducted.
What happens when distributions are withdrawn?
After hypothetical income tax, withdrawals leave invested assets and accumulate in a separate counter. They do not earn future returns. Unpaid accrued income remains a separately disclosed receivable until its hypothetical payment month.
Can this calculate a Treasury ladder?
No. Bills earn interest through purchase discounts, notes and bonds generally pay semiannual coupons, and direct TIPS adjust principal. This simulator approximates asset classes without individual maturity or coupon schedules.
Does a conservative case always grow?
No. The conservative illustration includes negative price changes, including −5% for dividend equities. Inflation can reduce real purchasing power even when nominal balances rise. You can inspect and edit every rate.
Are official rates used as future defaults?
No. Dated Treasury and CPI observations are read-only references. Planning rates are separate editable examples. Using historical CPI as a future assumption requires an explicit action and remains hypothetical. Official sites may restrict network access; U.S. accessibility was not verified.
How precise is the monthly ledger?
Balances use integer microdollars and half-up rounding per movement. Annual price and inflation factors use a fixed-point twelfth root. Tables display cents, so displayed rounded rows may differ by a cent; the underlying ledger reconciles exactly.