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.
How much do I need to retire? The tax math
The 25x rule ignores taxes. A single filer spending $60K a year needs $1.65-1.84M in a Traditional 401(k), not $1.5M. Here is the real math, worked in full.
7 best retirement planning apps for iPhone (2026)
The best retirement app depends on what you do on your phone. Quick scenario checks favor native iOS tools; multi-account planning belongs on desktop.
Retirement tax planning - 7 strategies
These 7 retirement tax strategies interact - one Roth conversion moves ACA subsidies, IRMAA, and Social Security tax at once. Sequencing is everything.
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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