Same numbers, programmatically. This page runs entirely in the browser; the same engine is also available as a JSON API and MCP server (see llms.txt). The projection is a standalone, dependency-free script for Node or a browser: https://www.a3sec.net/tools/engines/retire-engine.js. Example: curl -sO https://www.a3sec.net/tools/engines/retire-engine.js && node -e "const R=require('./retire-engine.js');console.log(JSON.stringify(R.summarize(R.computeRetirement({currentAge:30,currentSavings:10000,monthlyContribution:500,retirementAge:65,lifeExpectancy:85,retirementMonthlyExpenses:3000,returnRatePct:7,inflationRatePct:3})),null,1))"
Prefill by URL: retire.html?age=30&savings=10000&contribution=500&retireAge=65&lifeExpectancy=85&expenses=3000&return=7&tax=0&inflation=3&agent=1. Parameters: age, savings, contribution (per month), retireAge, lifeExpectancy, expenses (per month in retirement, today's dollars), return (% per year), tax (capital-gains drag, %), inflation (%), mode (real|nominal), lang (en|uk), theme (dark|light); agent=1 opens this panel. Results appear below as JSON (element id resultsJson).
Model. After-tax return = return × (1 − tax), applied as an annual drag; real return = (1 + after-tax) / (1 + inflation) − 1; monthly compounding with contributions added at the end of each month; nest egg needed = monthly expenses × annuity-due factor over the months in retirement at the real monthly rate; sustainable income = projected nest egg ÷ that factor; drawdown withdraws expenses at the start of each month. Contributions are constant in today's dollars and rise with inflation in nominal dollars. Nominal contributions sum the actual deposits; nominal gain/loss is the nominal nest egg minus those deposits. Other future values use (1 + inflation)^years. Currency-neutral.
No code execution? The same calculation is available as a JSON API (https://www.a3sec.net/api) and as MCP tools at https://www.a3sec.net/api/mcp. All three calculators are described in https://www.a3sec.net/llms.txt. Estimates only — not financial advice.
Current results (JSON, updated on every change):
{}