QuantCalc Retirement Engine

Runs the same plan against several published capital market assumption sets and returns the success rate and median outcome under each, showing how far the answer moves with the return forecast used. Every input is optional: omitted plan inputs use an illustrative plan (age 65, $1,000,000 saved, $40,000 a year spending) which the reply states in its first line.

Estimates a household's 2026 federal and state income tax return from its 2026 income (wages, Social Security, IRA and 401(k) distributions, pensions, Roth conversions, interest, dividends, capital gains and losses), deductions, withholding and estimated payments, and returns the federal refund or amount owed, the state refund or amount owed, and both together; the main Form 1040 lines (total income, AGI, deduction, taxable income, tax, total tax) and the state's taxable income and tax; and every default assumed, the facts the state engine assumed, and what is not modelled. Computed by QuantCalc's federal and state tax APIs, the engines the website's 2026 Return Preview is checked against to the cent. Requires a connected QuantCalc PRO licence or Tax Season Pass; without one it returns no figures and names the free web calculator. An estimate, not a filed return and not tax advice.

Runs a Monte Carlo retirement projection on the QuantCalc engine and returns the success rate, the ending-portfolio distribution, and the assumptions that produced them. The result states the return model that ran, the number of paths, and the income assumptions it used, including when there are none. Income tax is not modelled by this tool; run_tax_aware_projection models it.

Runs the retirement projection with the household's accounts split by tax type and returns the withdrawal order and Roth-conversion programme the engine selected, its present-value advantage and range against drawing traditional first, and the after-tax success rate. Federal and state income tax (50 states and DC), Social Security taxability, required minimum distributions, Medicare IRMAA surcharges and the early-withdrawal penalty are paid from the portfolio year by year; spending is what the household keeps after tax. The result states every assumption it used, including the defaults for inputs that were not given, and what the engine does not model.

Returns what the QuantCalc engine models and what it deliberately leaves out, including the tax provisions that are out of scope, and links to the published methodology.

Returns the published capital market assumption sets the engine carries and which components each publisher provides (returns, volatilities, correlations).

Searches every Social Security claiming age from 62 (or today's age) to 70 for the household's tax-aware plan: each age's benefit is the given benefit restated by the SSA reduction and delayed-retirement-credit rules, and each age runs the full tax-aware plan on the same simulated markets as the plan's own age. The score of a path is the after-tax estate minus unfunded spending (today's dollars); the result gives each age's success rate and median paired difference against the plan, the best age, and the 10th-90th percentile range. Requires a connected QuantCalc PRO licence. Long searches return a job_id: call again with only job_id to fetch the result.