What This Calculator Does
This tool applies to United States federal income tax and uses the 2024 tax year standard deduction amounts. When you file, the IRS lets you reduce your taxable income by either the flat standard deduction or the total of your itemized deductions — whichever is larger. This calculator adds up your itemized deductions, compares them to your standard deduction, and tells you which choice lowers your taxable income the most.
2024 Standard Deduction Amounts
Single: $14,600 · Married Filing Jointly: $29,200 · Married Filing Separately: $14,600 · Head of Household: $21,900. These are the figures used by this calculator. If you are 65+ or blind you may qualify for an additional amount not modeled here.
How to Use It
Pick your filing status, then enter your itemized deductions. The most common categories are state and local taxes (SALT, which is capped at $10,000), home mortgage interest, charitable contributions, and qualifying medical expenses that exceed 7.5% of your adjusted gross income. The result shows the larger value and a recommendation.
The Formula
$$\text{Deduction} = \max\Big(\text{Standard},\ \textstyle\sum \text{Itemized}\Big)$$ First, SALT is capped: \(\text{SALT}_{\text{used}} = \min(\text{SALT},\ 10{,}000)\). Then all itemized items are summed and compared to your standard deduction.
Worked Example
A married couple filing jointly (standard = $29,200) has $8,000 SALT, $9,000 mortgage interest, $3,000 charity, and $0 medical. Itemized total $$= 8{,}000 + 9{,}000 + 3{,}000 = \$20{,}000.$$ Since \(\$20{,}000 < \$29{,}200\), they should take the standard deduction of $29,200, which is $9,200 more than itemizing.
FAQ
Should I always itemize if I can? No — only itemize when your total itemized deductions exceed your standard deduction.
Why is SALT capped? The Tax Cuts and Jobs Act limits the combined deduction for state and local income, sales, and property taxes to $10,000 per return.
Is this tax advice? No. This is an educational estimate based on 2024 amounts. Consult a tax professional for your specific situation.
