Your cycle history, backed up and on every device
Every calculator stays free, forever. Pro is the private tracker upgrade: your log backed up and synced across your phone and laptop, and never sold or shared — $1.67 a month, billed yearly.
billed $19.99/year $59.88
Monthly
$4.99 / month
No account needed to buy · cancel anytime · 14-day refund · secure checkout by Stripe · refund policy
On every device, always in sync
Log on your phone, see it on your laptop. Your cycle history follows you automatically — no re-typing, no export files.
Backed up, never lost
A device-only log vanishes the moment you clear your browser or switch phones. Pro keeps a private backup so your history is safe.
Never sold, never shared
Selling your data isn't our business model. Your synced log travels over an encrypted connection and is used for one thing: showing you your own history.
Patterns in your own log
See which symptoms come back each cycle and on which days, and in which phase your mood and energy dip — worked out on your device from what you log.
Your full cycle history + a 12-month forecast
Every cycle's length and period length in one table, plus your next year of periods with an honest ± range from your own variation.
Doctor-ready report
A one-page summary of your cycles and patterns to print or save as PDF for an appointment. Made on your device — nothing is uploaded.
Support an independent, private tool
Period Tools has no ads and doesn't sell data, so subscriptions are what pay to keep every calculator free and private for everyone else.
What stays free — always
Pro never puts the basics behind a paywall. Every calculator, chart, and guide — period and ovulation, due date, pregnancy week-by-week, the pregnancy-safety A–Z, all of it — is free with no account and nothing logged. We think that’s how it should be. Pro adds a private, backed-up, synced tracker for the people who want it, and it’s what funds keeping everything else free. And right now the site runs no ads at all — if we ever add them to the free tier to help cover costs, Pro will always stay ad-free.
Privacy isn’t an add-on here
Selling cycle data is not how this tool makes money. The free tools run entirely in your browser, so your inputs never leave your device. Pro adds an account only so your tracker can follow you between phone and laptop — that synced log travels over an encrypted connection, is never sold or shared with advertisers, and you can delete it at any time. It’s the same promise either way: your cycle is your business, not ours to sell.
Frequently asked questions
- Do I need Pro to use the calculators?
- No. Every calculator, chart, and guide on Period Tools is free and always will be — no account, no login, nothing stored about you. Pro is an optional upgrade that adds a private tracker, backed up and synced across your devices, for people who want it.
- How is my data handled?
- The free tools run entirely in your browser — nothing about your inputs leaves your device. Pro adds an account only so your tracker can sync across your devices; that log travels over an encrypted connection, is never sold or shared, and you can delete it anytime. Unlike many period apps, selling your data isn't our business model.
- Can I cancel anytime?
- Yes. Pro is a simple subscription you can manage or cancel whenever you like from your dashboard, which links straight to the secure billing portal. No lock-in, no cancellation hoops.
- What does it cost?
- $19.99 a year, or $4.99 a month — well under what the big period apps charge. There's no lifetime plan; it's a straightforward subscription that keeps the free tools running.
— The Period Tools Team