Period Tools vs WorthCay

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 WorthCay
Detail	Period Tools	WorthCay
What it does	Free, accurate cycle and period predictor	Free Coast FIRE calculator to track your progress toward financial independence
Stage	Startup	Not given
Founded	2026	Not given
Based in	Not given	Not given
Pricing model	Freemium	Freemium
Pricing	All calculators and guides are free. Period Tools Pro (optional): $4.99/month or $19.99/year.	Free plan with 90-day trial: up to 20 accounts, 3 months snapshot history, multi-currency support, advanced charts, data export. Premium Monthly: $6/month with unlimited accounts and unlimited snapshot history. Premium Yearly: $59.99/year with all features unlocked.
Key features	Predicts next 6 periods Calculates ovulation day Identifies fertile window Private on-device tracking Cloud sync for Pro subscribers No signup required	Coast FIRE calculator FIRE number calculator Progress tracking over time What-if scenario testing Multi-currency support Advanced charts and analytics Data export in JSON and CSV
What makes it different	No data collection or server storage Uses standard medical calculation methods Honest about limitations and accuracy No aggressive marketing tactics	Organizes multiple real account types to match actual portfolio structure No signup required to run calculator; optional account for saving progress Immediate what-if analysis without reentering data
Community votes	0	0
DR (Domain Rating by Ahrefs)	15 +1 (up) since last check	9 no change since last check
Trust Flow (Majestic)	20	0
Citation Flow (Majestic)	9	18
Referring domains (Majestic)	77	10

5 details filled in for both companies.

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