Compare your taxes under the TCJA (Trump Tax Cuts) vs pre-2018 law. See SALT cap impact, doubled standard deduction, child credit changes, and actual savings.
The Tax Cuts and Jobs Act (TCJA), signed in December 2017, was the largest overhaul of the U.S. tax code in over 30 years. It reduced tax rates across every income bracket, nearly doubled the standard deduction, doubled the child tax credit to $2,000 per child, and capped the SALT (state and local tax) deduction at $10,000 — a provision that particularly affected taxpayers in high-tax states like New York, California, and New Jersey.
For most Americans, the TCJA resulted in lower federal income taxes. A family earning $100,000 typically saves $1,500-$3,000 per year. However, the SALT cap means some high-tax-state residents actually pay more, especially those with large property tax and state income tax bills exceeding $15,000-$20,000. The law also eliminated personal exemptions ($4,050 per person), partially offset by the higher standard deduction and expanded child credit.
This calculator lets you directly compare your results under TCJA rules versus the pre-2018 tax code. Enter your income, deductions, and family size to see exactly how the law changes your tax bill — and whether you benefit or lose from the key provisions.
With TCJA potentially sunsetting after 2025, understanding how the law affects your taxes is more important than ever. This calculator shows you exactly how much you save (or lose) compared to the old tax code, helping you plan for potential changes ahead. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain.
TCJA: Standard Deduction $14,600/$29,200 | SALT Cap $10,000 | Child Credit $2,000 | No personal exemptions | Rates 10-37% Pre-TCJA: Standard Deduction $6,350/$12,700 | No SALT Cap | Child Credit $1,000 | Personal Exemption $4,050/person | Rates 10-39.6% TCJA Savings = Pre-TCJA Tax − TCJA Tax
Result: TCJA tax $13,842 vs pre-TCJA $17,114 — saves $3,272
At $100K filing single: TCJA uses $14,600 standard deduction → $85,400 taxable. Pre-TCJA uses $6,350 standard + $4,050 exemption → $89,600 taxable at higher rates. TCJA bracket structure saves ~$3,272 annually.
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Individual TCJA provisions are set to expire after December 31, 2025 (unless extended by Congress). If the law sunsets, rates revert to pre-2018 levels, the standard deduction drops, personal exemptions return, and the SALT cap disappears.
Middle-income families with children benefit most (doubled child credit + higher standard deduction). High earners benefit from lower top rates (37% vs 39.6%). People in high-tax states with large SALT deductions may lose out due to the $10K cap.
TCJA capped the state and local tax (SALT) deduction at $10,000 total. Before TCJA, you could deduct unlimited property tax + state income tax. In high-tax states, people with $20K-$30K+ in SALT lose $2,000-$5,000+ in federal deductions.
TCJA eliminated the $4,050 per-person exemption but compensated by nearly doubling the standard deduction and increasing the child credit. For families with children, this was often net positive. Single filers without children typically still benefited from the larger standard deduction.
TCJA did not change the 0%/15%/20% long-term capital gains rates, but it adjusted the income thresholds. Short-term capital gains are still taxed as ordinary income at the new lower bracket rates.
TCJA dramatically raised AMT exemption amounts and phase-out thresholds, effectively removing AMT for most taxpayers. Before TCJA, about 5 million filers paid AMT; after, it affects far fewer people.