Patents, trademarks and copyright terms · Calculator

Patent Expiration Calculator
without the guesswork.

Patent Expiration Maintenance Fee Calculator — Separate the nominal U.S. patent-term estimate, PTA/PTE/disclaimer inputs, utility maintenance windows and live USPTO status. Uses a focused calculator with visible assumptions. Inputs stay in your browser.

Reference toolPatent Expiration Maintenance Fee CalculatorSeparate the nominal U.S. patent-term estimate, PTA/PTE/disclaimer inputs, utility maintenance windows and live USPTO status. Inputs stay in your browser.
Reference calculation
Inputs

Enter your details.

Your inputs are processed locally and are not uploaded to CalcSpan.

Section 1

Core details

Start with the information that defines this calculation.

Fri, Aug 21, 2026
Sat, Aug 21, 2021
Sun, Aug 21, 2016
Exclude a provisional filing unless the governing USPTO rule specifically uses another date.
Section 2

Review and confirm

Check the remaining facts before calculating.

Plain-date semantics · start date is not counted unless the result explicitly says inclusive.

Your result
Confirm the patent family, adjustments, disclaimer and live USPTO status

The tool separates the nominal patent-term estimate from utility maintenance-fee windows and live USPTO status. It does not declare a patent valid, enforceable or expired.

Record review dateAug 21, 2026
Patent typeUtility
Issue / grant dateAug 21, 2021
Earliest effective nonprovisional filingAug 21, 2016
Nominal term rule20 years from the earliest effective filing date
Nominal term endpointAug 21, 2036
PTA / PTE entered0 PTA days + 0 PTE days
Terminal disclaimerNone entered
Adjusted term estimateAug 21, 2036Subject to status, family, disclaimer and other legal issues
Patent Center / fee statusUnknown
Record reviewIncomplete
Latest maintenance stage paidNone / unknown
Next utility maintenance window7.5-year maintenance fee: Aug 21, 2028 – Feb 21, 2029 without surcharge; grace through Aug 21, 2029
Validity / enforceability / freedom to operateNot determined

Read before relying

Context matters.

  • USPTO says it does not determine individual expiration dates and provides its own detailed term calculator. Continuations, international filings, PTA/PTE, disclaimers, litigation and terminal events can change the analysis.
  • Utility maintenance fees can generally be paid without surcharge during years 3–3.5, 7–7.5 and 11–11.5 after issue, followed by six-month surcharge grace periods. The Maintenance Fees Storefront controls the live dates and amounts.
  • Design and plant patents do not have maintenance fees. Reissue utility patents require original-family and reissue-specific review and are intentionally blocked from the simple path.
Rule set 1.1.0

Sources & scope

Verified

This page shows the source trail, jurisdiction and review date alongside the result. Always confirm time-sensitive rules with the linked authority.

JurisdictionUnited States patent-record planning — USPTO family dates, term adjustments, disclaimers, maintenance windows and live status control
Review date2027-02-21
PrivacyNo input upload
Questions answered

What to know before using the result.

Is every U.S. patent simply twenty years from filing?

No. Utility and plant patents generally use the earliest effective filing date, while design patents use 14 or 15 years from grant. Pre-1995, reissue, PTA/PTE and disclaimer rules can change the result.

Which patents require maintenance fees?

Utility and reissue utility patents generally do. Design and plant patents do not have USPTO maintenance fees.

Does the estimated term date prove the patent is active or enforceable?

No. Live Patent Center and maintenance status, claims, disclaimers, court decisions and other legal issues control.