R&D Tax Credit Calculator — Methodology

Step-by-step calculation

Estimate the federal R&D tax credit amount and check qualified-small-business payroll-tax-offset eligibility.

1. 1

   Enter qualified researcher wages

   W-2 wages time-allocated to qualifying activities (not 100% of headcount payroll unless that's accurate).

2. 2

   Enter qualified supplies

   Consumables only — prototype materials, test fluids. Not capital equipment.

3. 3

   Enter contract research

   Third-party R&D payments — count at 65% per the IRS code.

4. 4

   Enter prior 3-year average QRE

   Zero for first-time claimers; the calculator applies the 6% ASC first-time method instead of 14% standard.

5. 5

   Check QSB eligibility

   Gross receipts below $5M with no receipts more than 5 years ago = eligible for payroll-tax offset (up to $500k/yr).

Assumptions and overrides

Implements the simplified ASC method only — not the regular method, which uses a 1984-89 base-period calculation almost no one needs. v1 doesn't model the four-part qualifying-activities test (permitted purpose, elimination of uncertainty, process of experimentation, technological in nature) — this calculator assumes the underlying activities qualify and computes the credit amount. Get a specialist R&D-credit firm or experienced CPA to qualify activities and prepare contemporaneous documentation; audit risk is the #1 reason casual credit claims fail.

Every region default on the calculator is editable. If your effective rate, fee, or threshold differs from the headline figure shown, type your own number into the field — the calculator recomputes instantly without leaving this page.

Primary sources

Region-tagged primary sources for the default rates, thresholds, and benchmarks used in this calculator.

• USAIRS — Form 6765 (R&D credit)
• USAIRS — IRC §41 Research Credit overview

Review cadence and corrections

This methodology and the underlying rate defaults are reviewed at least annually, and immediately following any change to the headline rate from IRS, HMRC, or SARS. Every substantive update is recorded on the public changelog. Spotted an error? See the corrections policy for how to report it.

See the full editorial policy for the standards every page on BusCalcTools is held to.