Essential Formulas - Patent Bar Prep

Fractured Crown: Mathematical Precision

The patent system runs on mathematics—precise calculations that leave no room for error. When Athelia learned these formulas during the download, she understood that numbers are the language of temporal boundaries.

Patent Term = 20 years from filing date (§ 154(a)(2)). This is immutable. No renewals, no extensions except PTA/PTE. The calculation is simple but absolute.

PTA (Patent Term Adjustment): When the USPTO delays examination beyond statutory timeframes, days are added back. A Delay + B Delay + C Delay - Applicant Delay = Total PTA. Complex, automated, and fiercely contested.

Fee calculations: Small entity (50% discount), micro entity (75% discount). Extension fees escalate monthly. Miss a payment, lose your rights.

These formulas are not suggestions—they are the precise mathematical rules governing every patent. Master them, and you can calculate deadlines, terms, and fees instantly during the exam.

📅 Patent Term Calculation

Base Patent Term (§ 154(a)(2))

Patent Term = 20 years from U.S. filing date

📌 Example:

Filing date: January 15, 2020
Expiration: January 15, 2040

⚠️ Important: For continuations/divisionals claiming priority, term is still 20 years from earliest U.S. non-provisional filing date (not from continuation filing date).

Patent Term with Priority Claim

Expiration = Earliest U.S. non-provisional filing + 20 years

📌 Example:

Parent filed: March 1, 2019
Continuation filed: June 15, 2020
Patent expires: March 1, 2039 (20 years from parent)

⚠️ Key Point: Provisional applications DO NOT count as "filing date" for term purposes. Term runs from non-provisional filing, even if claiming provisional priority.

Patent Term Adjustment (PTA) - § 154(b)

Adjusted Term = Base Term + PTA Days - Applicant Delay

📌 PTA Categories:

A Delay: USPTO failed to:
- Mail notice of allowance within 14 months of filing
- Respond to reply within 4 months
- Issue patent within 4 months of issue fee payment
B Delay: Application pending more than 3 years
C Delay: Interference, secrecy order, or successful appeal

📌 Example Calculation:

Filing: Jan 1, 2018
Issue: Jan 1, 2022 (4 years = 1461 days)
B Delay: 1461 - 1095 (3 years) = 366 days
Applicant delay: -120 days (late responses)
PTA = 366 - 120 = 246 days adjustment

Expiration: Jan 1, 2038 + 246 days = Sept 4, 2038

Design Patent Term

Design Term = 15 years from grant (AIA)
(14 years for applications filed before May 13, 2015)

⚠️ Key Difference: Design patents run from grant date, not filing date. No maintenance fees required for design patents.

Patent Term Extension (PTE) - § 156

Maximum Extension = Regulatory Review Period
(Max 5 years extension)

Total term from approval ≤ 14 years

📌 Example:

Patent filed: Jan 1, 2010 (expires Jan 1, 2030)
FDA review: 6 years
Drug approved: 2025

Extension requested: 6 years
Maximum allowed: 5 years (statutory cap)
Adjusted expiration: Jan 1, 2035

Term from approval: 2035 - 2025 = 10 years ✓ (< 14 year max)

⚠️ Important: § 156 only applies to FDA-regulated products (drugs, medical devices, food additives). Cannot combine PTA and PTE on same patent.

💰 Fee Calculations & Entity Status

Small Entity Definition

Small Entity = Person OR
Business with < 500 employees OR
University

Fee Multiplier: 0.5× (50% of undiscounted fee)

⚠️ Key Rule: All rights holders must qualify. If ANY owner (assignee, exclusive licensee) is large entity, CANNOT claim small entity status.

Micro Entity Definition (§ 123)

Micro Entity = Small Entity + ALL of:
• < 4 previously filed applications
• Gross income < 3× median household income ($200,000 approx)
• No assignment/obligation to assign to entity with > 3× income
• Not named on > 4 prior applications

Fee Multiplier: 0.25× (25% of undiscounted fee)

⚠️ Trap: Must re-certify micro entity status if circumstances change. Cannot claim micro if applicant doesn't qualify on filing date.

Extension of Time Fees

Extension Period	Undiscounted	Small Entity	Micro Entity
1st Month	$400	$200	$100
2nd Month	$1,200	$600	$300
3rd Month	$2,800	$1,400	$700
Maximum Extension	3 months (6 months total from OA mailing)

⚠️ Remember: Extensions are NOT available for restriction requirements or missing parts notices. Only for Office Actions under § 132.

Maintenance Fees (§ 41(b))

Due Date	Undiscounted	Small Entity	Micro Entity
3.5 years after grant	$2,000	$1,000	$500
7.5 years after grant	$3,760	$1,880	$940
11.5 years after grant	$7,700	$3,850	$1,925

Grace Period = 6 months after due date
(with late fee surcharge)

⚠️ Design Patents: NO maintenance fees required for design patents.

⏱️ Timing & Deadline Calculations

Response Deadline Calculation

Deadline = Mailing Date + Statutory Period + Extensions

Statutory Period (most OAs) = 3 months
Maximum Extensions = 3 months
Total Maximum = 6 months from mailing

📌 Example:

Office Action mailed: March 15, 2024
3-month deadline: June 15, 2024 (no fee)
+1 month extension: July 15, 2024 ($200 small entity)
+2 month extension: August 15, 2024 ($600 small entity)
+3 month extension: September 15, 2024 ($1,400 small entity)

Maximum deadline: September 15, 2024

⚠️ Weekend/Holiday Rule: If deadline falls on Saturday, Sunday, or federal holiday, deadline extended to next business day (37 CFR 1.7).

Priority Claim Deadlines

Priority Type	Deadline Formula	Statute
Provisional → Non-Provisional	Provisional date + 12 months	§ 119(e)
Foreign → U.S.	Foreign date + 12 months	§ 119(a)-(d)
PCT → National Stage	PCT date + 30 months	§ 365(c)
Parent → Continuation	Before parent issues/abandons	§ 120

⚠️ Copendency: For continuations/divisionals, parent and child must be copending for at least one day. File before parent issues or goes abandoned.

Abandonment Timing

Abandonment = Deadline + 1 day
(Application abandons day after deadline expires)

📌 Example:

OA mailed: January 1, 2024
6-month maximum deadline: July 1, 2024
Application abandons: July 2, 2024 (if no response)

Petition to revive: Can file within 2 years (unintentional)
Or immediately (unavoidable delay - harder standard)

Issue Fee Payment Deadline

Issue Fee Deadline = Notice of Allowance + 3 months

📌 Example:

NOA mailed: June 1, 2024
Issue fee due: September 1, 2024

If miss deadline: Application goes abandoned
Can revive if filed within 2 years

⚠️ Extensions: Issue fee deadline can be extended in 1-month increments (max 3 months) with fees.

Reissue Broadening Deadline

Broadening Reissue Deadline = Patent Grant + 2 years

📌 Example:

Patent granted: March 15, 2022
Broadening reissue deadline: March 15, 2024

After 2 years: Can only file narrowing reissue

⚠️ Key Point: Narrowing reissue can be filed anytime during patent term. Only broadening reissue has 2-year limit.

📋 Quick Reference Card

Most Common Calculations

What to Calculate	Formula
Patent expiration	Earliest U.S. non-provisional filing + 20 years
Provisional priority deadline	Provisional filing + 12 months
Foreign priority deadline	Foreign filing + 12 months
PCT national stage deadline	PCT filing + 30 months
OA response deadline	Mailing + 3 months (extendable to 6)
Issue fee deadline	NOA + 3 months
Broadening reissue deadline	Grant + 2 years
Small entity fee	Undiscounted × 0.5
Micro entity fee	Undiscounted × 0.25
Design patent term	Grant + 15 years (AIA)