CertCheck

SSL Certificate Expiry Calculator

Enter issue and expiry dates — see how many days remain and whether renewal is needed.

Not Before (issued)

Not After (expires)

What you entered

Issued: 2026-08-01Expires: 2026-10-30

1
Certificate validity period
2026-10-30 − 2026-08-01= 90 days
2
Days remaining from today
2026-10-30 − today= 53 days
3
Status
More than 30 days= Valid

Result

Status: 53 days remaining

This certificate has 53 days remaining out of its 90-day validity period.

Certificate validity periods and renewal windows

Days remaining is the expiry date minus today. These rows are worked against a reference date of 7 September 2026 to show how each validity period lands.

Issued	Expires	Total validity	Days remaining	Status
2026-06-01	2026-08-30	90 days	-8	Expired 8 days ago
2026-09-06	2026-09-21	15 days	14	Renew soon
2026-08-01	2026-10-30	90 days	53	Valid
2026-01-01	2027-01-01	365 days	116	Valid
2026-09-01	2027-10-04	398 days	392	Valid

398 days is the maximum lifetime public certificates may be issued for, and the CA/Browser Forum has agreed to reduce this in stages toward 47 days by 2029. Let's Encrypt issues 90-day certificates, which is why automated renewal is now the norm rather than a convenience.

Why SSL certificates expire

SSL/TLS certificates expire to ensure periodic re-validation of domain ownership and to limit damage from compromised private keys. Most certificates are now valid for 1 year (398 days max since 2020). Let's Encrypt certificates expire every 90 days, encouraging automation.

When to renew

Renew at least 30 days before expiry to avoid downtime. An expired certificate causes browsers to show security warnings, which can drop traffic by 90%+. Automate renewal with certbot or your hosting provider's auto-renewal feature. Monitor expiry dates with uptime tools.

Frequently asked questions

My certificate was issued January 15 and expires January 14 next year — how many days left?

Enter both dates above and the calculator shows the exact days remaining and whether renewal is recommended. With certificates valid for 398 days max, planning renewal at the 30-day mark avoids surprise expiration.

What happens if my SSL certificate expires?

Browsers show a full-screen security warning that most visitors won't click through. Google Chrome shows 'Your connection is not private.' Traffic can drop by 90%+ until the certificate is renewed.

How often should I renew my SSL certificate?

Let's Encrypt certificates expire every 90 days (automate renewal with certbot). Commercial certificates typically last 1 year (398 days max since 2020). Renew at least 30 days before expiry to catch any issues.

Can I get a free SSL certificate?

Yes. Let's Encrypt provides free, automated certificates trusted by all major browsers. Most hosting providers (Cloudflare, Netlify, Vercel) also include free SSL. Paid certificates from DigiCert or Sectigo add extended validation (EV) features.