Plug in your numbers across mileage, home office, cell/internet, health insurance, retirement, and meals. Compare 2025 and 2026 rates side-by-side. Estimates only — not tax advice. Verify against current IRS guidance for your situation.
Standard mileage method. Multiply business miles by the IRS rate. 2025: 70¢/mile · 2026: 72.5¢/mile.
$5 per square foot of business-use space, capped at 300 sq ft = $1,500 maximum. Same rate for 2025 and 2026. Space must be regularly AND exclusively used for the business.
Deductible at your business-use percentage. Be honest — the IRS expects a reasonable, documentable allocation.
As a more-than-2% S-Corp shareholder, premiums the corp pays on your behalf (and reports in your W-2 Box 1) are deductible above the line on your 1040 — full amount, no AGI floor. Structural rule; no rate change between years.
Conservative SEP-IRA / Solo 401(k) employer-side estimate: 25% of W-2 wages from the S-Corp, capped at the annual IRS limit. 2025 cap: $70,000 · 2026 cap: $72,000. Excludes employee-deferral elections and age-50+ catch-up.
50% of qualifying business meals are deductible (post-2022; the 100% COVID-era allowance expired). Same 50% rate for 2025 and 2026. Meal must have a business purpose and be substantiated.
Combined deduction across all six categories — and what that could mean in tax savings at three common federal brackets. (Federal-only; doesn't include state or payroll-tax interactions.)
One-page summary of your numbers, plus a short action checklist for each of the six categories: what to track, what to document, and what to ask your CPA. Free.
By submitting, you'll receive the PDF and occasional notes from MCKI. Unsubscribe any time. Prefer to talk to me first? →Estimates only. Not tax or legal advice. This calculator uses standard IRS rates as published; your actual deductible amounts depend on facts I don't have here — substantiation, allocation methods, basis limitations, AGI thresholds, state rules, and the rest. Verify against current IRS guidance for your situation, or have a CPA confirm before you act.
I'm a bookkeeper, not a CPA, not an enrolled agent, and not a tax preparer. I don't prepare returns or give tax advice. What I do is keep books that a CPA can actually file from — that's the service that makes deductions like these provable, not just plausible.
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