Period Tools vs Coast FIRE Planner

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 Coast FIRE Planner
Detail	Period Tools	Coast FIRE Planner
What it does	Free, accurate cycle and period predictor	Find the month you can stop saving for retirement
Stage	Startup	Not given
Founded	2026	Not given
Based in	Not given	CA
Pricing model	Freemium	Free
Pricing	All 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	Shows the exact month you can stop saving Runs 1,000 simulated markets to show odds of success What-if scenarios for savings, returns, and fees Accounts for investment fees and contribution raises Share links to compare plans with others No sign-up required Calculations run in browser, data not stored Shows formulas and assumptions transparently
What makes it different	No data collection or server storage Uses standard medical calculation methods Honest about limitations and accuracy No aggressive marketing tactics	Answers when you can stop saving, not just how much you need No sign-up, no data stored, free to use Shows odds of success with Monte Carlo simulations Plain language explanations without financial jargon or hype
Community votes	0	0
DR (Domain Rating by Ahrefs)	15 +1 (up) since last check	Not checked yet no change since last check
Trust Flow (Majestic)	20	0
Citation Flow (Majestic)	9	16
Referring domains (Majestic)	77	2

4 details filled in for both companies.