Standard vs. itemized deduction calculator

Add up your itemized deductions, compare them to the 2024 standard deduction, and see the threshold you have to clear — plus what itemizing is actually worth at your marginal rate.

The SALT field is capped at $10,000 automatically — that is the deduction limit for state, local, and property taxes combined, not a typo. Everything above the cap is thrown away before the comparison runs.

How the math works

There is no formula to memorise here. You take whichever number is larger — your total itemized deductions or the flat standard deduction for your filing status. The tax code hands you the standard deduction for free; you only itemize when your own deductions beat it.

The 2024 standard deduction is $14,600 for a single filer and $29,200 for a married couple filing jointly. The one figure that decides everything is the gap between your itemized total and that number. If you are below it, itemizing saves you nothing — you take the standard and the itemized total is irrelevant. If you are above it, only the excess counts, and it is worth your marginal rate in tax. Extra deduction of $5,400 at a 22% marginal rate saves $1,188, not $5,400.

Worked example

Take a single filer with $11,000 in itemizable deductions — mortgage interest, state tax, and charity added together — against the 2024 standard deduction of $14,600.

The standard deduction wins by $3,600. That is the gap this filer would have to close before itemizing does anything at all. Not $1 of their $11,000 in deductions changes their tax bill, because the standard deduction already covers more. They file the standard deduction, skip the receipts, and pay exactly what a renter with no deductions pays.

This is the outcome for most filers now. After the 2017 law nearly doubled the standard deduction, the share of filers who itemize fell from roughly 30% before 2018 to fewer than 12% after. The mortgage-interest deduction only helps a filer who itemizes, so most homeowners get no federal tax benefit from it at all.

When this calculator is wrong

This tool answers a single-year federal question. Two things it does not model can flip the right answer.

Your state may force the choice

Several states tie the state return to the federal one. The District of Columbia and Virginia require a filer who takes the standard deduction federally to take it on the state return too, and a filer who itemizes federally to itemize on the state return. Maryland requires the two to match only when you claim the federal standard deduction. In those states the choice that minimises your federal tax can raise your combined federal-plus-state bill, because your state deductions might clear the state threshold even when your federal ones fall short of the federal standard. The only way to know is to run both returns both ways. A federal-only calculator — this one included — cannot see it.

The standard deduction is an annual floor, so the year you spend counts

Because you get the standard deduction every year whether you spend anything or not, itemizable deductions below the threshold are wasted, year after year. The move against that is bunching: push two years of deductible giving into one calendar year so that year clears the threshold, then take the standard deduction in the off year. A donor-advised fund is the usual vehicle — you take the full deduction in the year you fund it and let the grants go out over time.

Say a single filer sits at $11,000 a year and can time their giving. Take the standard both years and they deduct $14,600 twice, for $29,200. Bunch two years of giving into one and suppose that year's itemized total reaches $17,000; they itemize the bunch year and take the $14,600 standard the next, deducting $31,600 across the two years. The $2,400 of extra deduction is worth $528 at a 22% rate. The single-year snapshot above never shows this, because it only looks at one year at a time.

What to do with the result

For most people, the honest answer is take the standard deduction and stop tracking receipts. After the 2017 standard deduction nearly doubled, fewer than 12% of filers itemize, and to beat the 2024 single standard deduction of $14,600 you need substantial mortgage interest plus state taxes plus charity. Many households who itemized before 2018 stopped because the standard deduction now covers more. The exception is high-income households in high-tax states with large mortgages, who still itemize and benefit — for them the $10,000 SALT cap is the binding constraint.

If the calculator puts you within a few thousand dollars of the threshold, that is the case where bunching, a donor-advised fund, or timing an elective medical expense into the right year can tip you over. If you are far below it, none of that is worth your time — take the standard and move on.

Common questions

Can I take the standard deduction and itemize?

No. It is one or the other, per return, per year. You compare the two totals and take the larger. The only nuance is timing across years — see bunching above.

Does the SALT cap really limit my deduction to $10,000?

Yes, for tax years 2018 through 2025. State and local income (or sales) tax plus property tax are added together and capped at $10,000 per return, $5,000 if married filing separately. Anything above that is not deductible. It is the main reason former itemizers in high-tax states now fall below the standard deduction.

Why doesn't my mortgage interest lower my taxes?

Mortgage interest is only deductible if you itemize. If your itemized total is below the standard deduction, you take the standard, and the mortgage interest changes nothing on your federal return. Most homeowners are now in this position.

How much are my deductions actually worth?

Only the amount by which your itemized total exceeds the standard deduction, and only at your marginal rate. If you itemize $20,000 against a $14,600 standard, the deduction "worth" is the $5,400 excess times your marginal rate — about $1,188 at 22%, not the full $20,000.

What counts toward itemized deductions?

The common ones: state and local taxes (capped at $10,000), home mortgage interest, charitable gifts, and unreimbursed medical expenses above 7.5% of your adjusted gross income. The medical floor is high enough that most filers never clear it.