R&D Tax Credit Calculator: Federal and State Credits

Enter your qualified research wages, supplies, and contract research, your research history, and your gross receipts, and the calculator estimates the federal research credit under both methods, the startup payroll tax offset, and a state credit for California, Texas, or Illinois.

Short answer: the federal research credit under IRC §41 is usually figured with the alternative simplified credit (ASC): 14% of this year's qualified research expenses (QREs) above 50% of your average QREs for the prior three years. If you had no QREs in any one of those three years, it is a flat 6% of this year's QREs. A start-up with gross receipts under $5 million can apply up to $500,000 of the credit against payroll taxes each year.

The calculator is for informational purposes only and gives estimates, not a completed Form 6765. Credits are shown before the general business credit limitation, the section 280C(c) choice, and any audit adjustments, and the state figures are simplified.

What do you enter in the R&D credit calculator?

How the federal credit is calculated

The Form 6765 instructions give two ways to figure the credit, and the calculator shows both and keeps the larger.

Step 1: qualified research expenses. QREs = wages + supplies + 65% of contract research. The 65% rule is in §41(b)(3)(A); payments to a qualified research consortium count at 75%, and payments to certain small businesses, universities, and federal labs at 100% for energy research, which the calculator does not separate out.

Step 2a: regular credit. 20% of QREs above a base amount. The base is your fixed-base percentage times your average gross receipts for the prior four years, but two limits apply:

• The base can never be less than 50% of current-year QREs (§41(c)(2)), so the regular credit can never exceed 10% of QREs.
• The fixed-base percentage can never exceed 16% (§41(c)(3)(C)).

Step 2b: alternative simplified credit. 14% of QREs above 50% of the average QREs for the prior three years. If you had no QREs in any one of those three years, the ASC is 6% of current QREs instead (§41(c)(4)(B)).

Step 3: reduced credit choice. Under section 280C(c), you either reduce your research deduction by the full credit or elect a reduced credit: 15.8% instead of 20% under the regular method and 79% of the ASC. The results show the 79% figure next to the full credit.

Worked example: the default inputs

A C corporation in California pays $500,000 of research wages, uses $100,000 of supplies, and pays $200,000 to a contract engineering firm. Its prior three years averaged $400,000 of QREs, its fixed-base percentage is 3%, and its average gross receipts are $10 million.

The ASC wins by $1,200, and the 50% minimum base is what holds the regular credit down: without it, the regular credit would have been 20% × $430,000 = $86,000.

Can a start-up use the credit against payroll tax?

Yes, if it is a qualified small business under §41(h)(3): gross receipts of less than $5 million for the tax year, and no gross receipts for any tax year before the five-tax-year period ending with that year. A company in its first, second, or third year of revenue under $5 million qualifies; a 10-year-old company with $3 million of revenue does not. There is no minimum credit amount.

The election is capped at $500,000 for tax years beginning after 2022: $250,000 against the employer's 6.2% Social Security tax plus, since the Inflation Reduction Act, another $250,000 against the employer's 1.45% Medicare tax. It can never exceed the credit for the year, and a business can make it for no more than five tax years. You make the election on a timely filed Form 6765 and claim the offset on Form 8974 with your payroll returns, starting with the first quarter after you file the income tax return.

Worked example: a three-year-old start-up

A software company in its third year of revenue has $1.2 million of gross receipts. It pays $400,000 of research wages, $50,000 of supplies, and $100,000 of contract research. It had no QREs in its first year, so one of the three prior years is zero.

1. QREs: $400,000 + $50,000 + $65,000 = $515,000.
2. ASC: no QREs in a prior year, so 6% × $515,000 = $30,900.
3. Regular credit: start-ups use a 3% fixed-base percentage; 3% × $800,000 average receipts = $24,000, which is below the 50% minimum of $257,500, so the credit is 20% × $257,500 = $51,500.
4. The regular credit is larger. Because receipts are under $5 million and the company has had receipts for only three years, it can elect to apply all $51,500 against its payroll taxes, which matters because a company with losses has no income tax to offset.

For a young company, the regular method with the 3% start-up percentage often beats the 6% ASC, so it pays to run both.

How the state credits are estimated

The calculator assumes all of your research and gross receipts are in the state you pick and uses the federal QRE definition.

California dropped its alternative incremental credit and adopted a California version of the ASC for tax years beginning on or after January 1, 2025. The calculator takes the larger of the regular and ASC results; the 24% credit for basic research payments to universities is not included.

Texas replaced its old 5% franchise tax credit and the sales tax exemption for research with a new credit for franchise tax reports originally due on or after January 1, 2026 (Texas Comptroller). The rate rises to 10.903% (5.451% without history) when research is done under a contract with a college or university, which the calculator does not model, and an entity that owes no franchise tax because of the no-tax-due threshold can receive the credit as a refund. In the default example, the Texas credit would be 8.722% × ($730,000 − $200,000) = $46,226.60.

Illinois uses an incremental 6.5% credit; in the default example that is 6.5% × ($730,000 − $400,000) = $21,450. Check that the credit is in effect for your tax year on the current Schedule 1299-D.

Pick "Other State" for everywhere else. Many other states have research credits, but their formulas differ too much to estimate reliably here.

What changed for research costs in 2025?

The One Big Beautiful Bill Act added section 174A. For tax years beginning after December 31, 2024, you can again deduct domestic research and experimental expenditures in the year you pay them, or elect to amortize them over at least 60 months; foreign research is still amortized over 15 years. Companies that capitalized domestic research costs in 2022 through 2024 have transition options for the unamortized amounts, covered in Rev. Proc. 2025-28. The credit itself did not change. What changed is the interaction: if you take the full credit, you reduce your section 174A deduction (or the capitalized amount) by the credit, which is why the reduced-credit election under section 280C(c) is worth comparing.

What counts as qualified research?

Activities have to pass all four parts of the §41(d) test:

1. Research and experimental purpose. The costs qualify as research and experimental expenditures (section 174A for domestic research), aimed at a new or improved product, process, software, technique, formula, or invention.
2. Technological in nature. The work relies on physical or biological sciences, engineering, or computer science.
3. Elimination of uncertainty. At the start, you were uncertain about capability, method, or the right design.
4. Process of experimentation. You evaluated alternatives through modeling, simulation, or systematic trial and error.

Excluded: research after commercial production begins, adapting or duplicating an existing product, surveys and market research, routine quality testing, research conducted outside the United States, and research funded by someone else (for example, a customer contract where you don't bear the risk of failure).

Common mistakes the calculator helps you catch

• Counting all contract research. Only 65% counts, and only if you pay regardless of success and keep substantial rights to the results.
• Ignoring the minimum base. A low fixed-base percentage does not make the regular credit 20% of QREs; the 50% floor caps it at 10%.
• Assuming the ASC is always 14%. One prior year without QREs drops it to 6%.
• Using the old $250,000 payroll cap. The limit has been $500,000 for tax years beginning after 2022.
• Thinking the payroll election needs a $25,000 credit. There is no such threshold; the tests are $5 million of receipts and five years.
• Taking the full credit and the full deduction. Without the 280C(c) election, the research deduction must be reduced by the credit.

Where the credit goes on the return

C corporations claim the credit on Form 6765 and Form 3800. For S corporations and partnerships, the credit passes to shareholders and partners on Schedule K-1, and each owner's own tax limits what they can use. Unused general business credit carries back one year and forward 20 years. Eligible small businesses (average gross receipts of $50 million or less) can use the credit against alternative minimum tax. To estimate an S corporation owner's wages and payroll tax, use the S corp payroll tax calculator; for the pass-through deduction on the same income, the QBI deduction calculator.