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.
Social Security Tax Calculator: How Benefits Get Taxed
Up to 85% of Social Security benefits are federally taxable, based on provisional income thresholds frozen since 1983. Here is the formula, the tax torpedo, and how to minimize it.
Required Minimum Distribution Rules: Age, Deadlines, Penalties
Under SECURE 2.0, required minimum distributions start at age 73 (born 1951–1959) or 75 (born 1960+), with a reduced 25% penalty for missed distributions and no RMDs for Roth 401(k)s.
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.
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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