R&D Tax Credit Calculator (Section 41)
Compute the IRC §41 R&D Tax Credit using the Alternative Simplified Credit (ASC) method. The calculator separates the credit into the §41(h) payroll-tax-election portion (up to $500K for qualified small businesses, post-IRA) and the residual income-tax credit. Source-cited to IRC §41 and IRS Form 6765.
§41(h) cap: $500,000
Subject to §38(c) general-business-credit limits
Eligible: current-year gross receipts of $1,500,000 are under the $5M QSB limit, and the entity has had gross receipts in only 3 prior tax years.
No usable 3-year QRE history — using the §41(c)(5)(B)(ii) startup formula.
View the TypeScript implementation on GitHub: packages/calc/src/rd-tax-credit.ts · view tests
R&D credit rules at a glance
Key facts
- The ASC formula
- The Alternative Simplified Credit (IRC §41(c)(5)) is 14% of current-year QREs above 50% of the average prior-three-year QREs — or 6% of current QREs when no usable three-year history exists (the startup formula).
- The payroll-tax election
- IRC §41(h) lets a Qualified Small Business apply up to $500,000 of the R&D credit against employer FICA payroll tax instead of income tax — the difference-maker for pre-revenue startups that would otherwise strand the credit as a carryforward.
- Who qualifies as a QSB
- Both tests must pass under IRC §41(h)(3): current-year gross receipts under $5,000,000 AND gross receipts in no more than 4 prior tax years. A single $500 invoice in an early year counts as a full year of receipts.
- What the IRA changed
- The Inflation Reduction Act of 2022 (P.L. 117-169 §13902) doubled the payroll-tax-credit cap from $250,000 to $500,000 for tax years beginning after December 31, 2022, and extended the offset to the Medicare portion of employer FICA after Social Security is fully offset.
- Contractor research
- Contract research counts at only 65% of the contracted amount (IRC §41(b)(3)), and only when the company bears the financial risk and retains substantial rights in the IP. Foreign-performed research generally does not qualify.
What this means
The R&D credit is the most under-used tax incentive available to technical-product companies. The math is easy: 6% of current QREs for a startup with no prior history, or 14% of the incremental amount above 50% of the trailing 3-year average. The hard part is substantiating which expenses count as QREs — and most companies leave money on the table because they don't track engineering time against the four-part test contemporaneously.
The payroll-tax election under §41(h) is the structural lever that actually moves cash. A pre-revenue startup with $3M of QREs gets a $180K credit; without the election, that's a carryforward sitting on the balance sheet doing nothing. With the election, it offsets actual employer payroll-tax payments quarter by quarter starting the quarter after the return is filed. The 2022 IRA doubled the cap from $250K to $500K, which means an early-stage company with $8M+ of QREs now pulls $500K of cash out of the IRS instead of $250K. The election is irrevocable for the year — make it deliberately, not by accident.
Worked example
3-year-old SaaS startup. Two engineering hires plus the founder spent most of 2026 building the core product. Total wages allocated to qualified research activity: $2.4M. Cloud/dev-tools spend traceable to product development: $400K. Contract designer/specialist work (eligible at 65%): $200K × 0.65 = $130K. Aggregate current-year QREs: approximately $2.93M; rounded to $3.0M. No prior QRE filings (this is the first §41 claim). Current-year gross receipts: $1.5M (early-stage SaaS, mostly trial conversions). Three prior tax years with receipts.
ASC method: startup 6% formula (no usable 3-year history). Credit = 6% × $3.0M = $180,000. QSB eligibility: gross receipts $1.5M (under $5M ✓), 3 prior years with receipts (≤ 4 ✓) — eligible. Payroll-tax election made. Applied to payroll tax: $180,000 (under the $500K cap). Applied to income tax: $0. The takeaway: a 3-person engineering team in its first year of meaningful QRE substantiation pulls $180K of cash back from the IRS over the four quarters following filing — roughly the cost of the next senior engineer hire.
Frequently asked questions
The information and tools on this website are for general educational purposes only and do not constitute financial, investment, legal, or tax advice. Consult a licensed professional for decisions specific to your situation.