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Period Tools vs firenum™

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

Period Tools compared with firenum™
DetailPeriod Tools logo Period Toolsfirenum™ logo firenum™
What it doesFree, accurate cycle and period predictor Free FIRE financial planner with Monte Carlo simulation and historical backtesting
StageStartup Established
Founded2026 2019
Based inNot given Not given
Pricing modelFreemium Free
PricingAll calculators and guides are free. Period Tools Pro (optional): $4.99/month or $19.99/year. Not given
Key features
  • Predicts next 6 periods
  • Calculates ovulation day
  • Identifies fertile window
  • Private on-device tracking
  • Cloud sync for Pro subscribers
  • No signup required
  • Monte Carlo simulation with up to 5,000 runs
  • Historical backtesting against every market period since 1872
  • US federal, state and payroll tax calculations for all 50 states
  • Roth conversion ladder and RMD planning
  • Six stress tests including market crash and job loss
  • Three withdrawal strategies with 59.5 rule enforcement
  • Support for 9 asset types with individual growth rates
  • Month-by-month income and expense modeling with custom timelines
  • Life event planning
  • 9-currency support with auto-detection
What makes it different
  • No data collection or server storage
  • Uses standard medical calculation methods
  • Honest about limitations and accuracy
  • No aggressive marketing tactics
  • Runs entirely in your browser with no account needed or data stored on servers
  • Tests retirement against 154 years of historical market data since 1872
  • Calculates exact tax liability for all 50 US states plus federal and payroll taxes
  • Completely private with no data collection, selling or sharing
  • Works offline on Android with full planner functionality
Community votes00
DR (Domain Rating by Ahrefs)15 +1 (up) since last check12 no change since last check
Trust Flow (Majestic)204
Citation Flow (Majestic)934
Referring domains (Majestic)77127

6 details filled in for both companies.

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