Authoritative Data Sources & Reference Standards
BusinessCalc maintains strict source transparency for all rate-driven and statutory calculators. We rely exclusively on official federal publications, statutory tax codes, and regulatory framework directories. Below is the complete, live-verified index of primary sources powering our platform.
| Source | Powers on BusinessCalc | Vintage | Link |
|---|---|---|---|
| IRS Publication 946 | MACRS depreciation rates (3/5/7/15-yr, half-year convention) | 2026 tax year | irs.gov/publications/p946 |
| IRS Form 4562 · Pub 538 | Depreciation election & accounting-method rules | current | irs.gov/forms-pubs/about-form-4562 · irs.gov/publications/p538 |
| IRC §11 (26 U.S.C.) — Cornell LII | Federal corporate income tax rate (flat 21%) | current | law.cornell.edu/uscode/text/26 |
| Tax Foundation — State Corporate Tax Rates | State corporate income tax rates | 2026 | taxfoundation.org/state-corporate-tax-rates |
| FASB (ASC 740, Income Taxes) | Income-tax accounting / effective tax rate method | current standard | fasb.org |
| SSA / IRS | Social Security wage base ($176,100 for 2026); Medicare 1.45% | 2026 | irs.gov |
| IRS Form 940 | FUTA rate (6% gross / 0.6% net) & $7,000 wage base | current | irs.gov/forms-pubs/about-form-940 |
| DOL / ETA state UI directory | State unemployment (SUTA) wage bases & rates | current (link-out; varies by state) | oui.doleta.gov/unemploy/statelaws.asp |
| IRS Publication 15 (Circular E) | Federal payroll withholding | 2026 tax year | irs.gov/publications/p15 |
| eCFR 29 CFR Part 778 | FLSA overtime — weighted-average regular rate (1.5×) | current regulation | ecfr.gov/title-29/part-778 |
Definitional Standards for Pure-Formula Calculators
Formula-only calculators (EBITDA, DSCR, CCC, NPV, IRR, EOQ, DSO, break-even, ratios) compute live in your browser using standard finance and accounting definitions established by the FASB Accounting Standards Codification (GAAP), the CFA Institute, and the AICPA — they consume no external data feed.