Startup tax math, instantly.
Free calculators for the numbers founders actually have to get right — from R&D capitalization to QSBS to Delaware franchise tax. No login, no email.
Tax
Section 174 Calculator
Estimate how much R&D you can deduct now vs. capitalize under §174A — and the phantom tax a foreign engineering team creates.
R&D Tax Credit Calculator
Estimate the federal R&D tax credit your startup can claim, including the payroll-tax offset available to qualified small businesses.
QSBS Calculator
Estimate your potential QSBS gain exclusion under Section 1202 — up to $10M (or 10x basis) of tax-free gain at a qualifying exit.
First-Year Tax Checklist
An interactive checklist of the tax filings, elections, and deadlines a newly incorporated startup must handle in its first year.
Compliance & deadlines
Delaware Franchise Tax
Calculate your Delaware franchise tax both ways — authorized shares vs. assumed par value — and see which method the state uses.
83(b) Deadline Calculator
Find your 83(b) election filing deadline — exactly 30 days from your grant date, with no extensions and no exceptions.
Nexus Self-Check
Check which states your startup may have income or sales-tax nexus in, based on employees, revenue, and physical presence.
State Deadline Lookup
Look up state franchise tax and annual report deadlines for your entity, so you never miss a state-level filing date.
Fundraising
These tools give planning estimates, not tax advice. Acorn 9 is a tax & accounting firm built for startups — when it's time to file, a licensed CPA prepares and signs the return.