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.
Retirement Tax Planning: 7 Strategies to Keep More
These 7 retirement tax strategies interact — a Roth conversion changes your ACA subsidies, IRMAA, and Social Security taxation simultaneously. Here's the sequencing most advice misses.
The 4% Rule Is Wrong: What Monte Carlo Shows
The 4% rule was designed for 30-year retirements. Monte Carlo simulation shows a 15-20% failure rate over 50 years. Here's what actually works for early retirees.
Tax-Efficient Retirement Withdrawal Strategies
The optimal withdrawal strategy combines taxable account spending with Roth conversions to fill low tax brackets — saving $100,000–300,000+ vs. the conventional sequential approach.
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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