Retirement planning, simplified
The only iOS calculator that does marginal tax brackets, capital gains stacking, and Social Security taxation correctly. 17 analysis tools. Zero data collection.
What makes CoastIQ different
No App Store competitor does tax math correctly. CoastIQ does.
Tax-Accurate Projections
Marginal federal brackets, capital gains stacking, Social Security taxation, NIIT, state taxes, FICA, and IRMAA — computed correctly.
Monte Carlo Simulation
1,000+ trial parallel simulation with correlated stock/bond returns and historical backtesting from 1928 to today.
Roth Conversion Optimizer
Bracket-filling strategy that respects ACA subsidies and IRMAA thresholds. Year-by-year conversion plan with incremental tax.
100% On-Device
All computation happens on your iPhone or iPad. No cloud, no accounts, no data collection. Your financial data never leaves your device.
17 analysis tools
From the blog
Tax strategies, FIRE planning guides, and retirement calculator deep-dives.
Tax-efficient retirement withdrawal order
Combine taxable-account spending with Roth conversions to fill the low tax brackets and save $100,000 or more versus the conventional sequential drawdown.
When to claim Social Security - break-even
The pre-tax break-even for claiming Social Security at 62 versus 70 is age 80. Taxes on how benefits stack with other income can shift it 6 to 12 months.
Why most retirement calculators get taxes wrong
Most retirement calculators use flat tax rates or ignore taxes entirely. Here's what they miss and why it costs you tens of thousands in bad planning.
Plan your retirement with confidence
Free dashboard with success rate, metrics, and projection chart. Upgrade to Pro for all 17 tools, unlimited scenarios, and PDF exports.
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