Itemized Deduction Calculator
What you paid, and the limits that apply
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- United States unless the calculator explicitly says otherwise
- Rules and time period
- Tax years supported by the selected calculator
- Scope and limitations
- Educational estimate only, not a tax return or filing determination. U.S. statutory-threshold tools use USD. Confirm current law and your facts with the relevant authority or a qualified tax professional.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter your AGI first — four of the limits on this page are a percentage of it.
- 02
Enter your state and local income tax and your property tax. Together they are capped, so the two are read as one line.
- 03
Enter mortgage interest paid and the loan balance it was paid on. Only interest on acquisition debt up to the limit counts, and the balance is what decides how much of it survives.
- 04
Add charitable gifts and out-of-pocket medical expenses. Each meets a floor set as a share of your AGI.
- 05
Read the total, then the schedule: what you paid, what counts, and what each limit removed on the way.
Formula
SALT = min(state and local tax + property tax, the cap). Mortgage = interest × (acquisition-debt limit ÷ balance) when the balance is larger. Charity = gifts above the AGI floor, capped at the AGI ceiling. Medical = expenses above the AGI floor. Total = the four added, less 2/37 of the lesser of that total or taxable income above the 37% bracket.
Example
On $285,000 of AGI: $45,500 of state and property tax is cut to the $40,400 cap, losing $5,100. $27,400 of interest on an $820,000 balance is prorated to the $750,000 limit, keeping $25,061. $6,200 of gifts meets a $1,425 floor, leaving $4,775. $4,100 of medical is under the $21,375 floor entirely. So $83,200 paid becomes $70,236 deducted — $54,136 above the standard deduction, worth $17,324 at a 32% rate.
Definitions
- SALT
- State and local tax: income or sales tax plus property tax, deductible together only up to the cap.
- Acquisition debt
- A mortgage used to buy, build or substantially improve the home. Only interest on this, up to the limit, is deductible.
- AGI floor
- A threshold expressed as a share of AGI that an expense must exceed before any of it counts — 7.5% for medical, 0.5% for charitable gifts from 2026.
Good to know
Why most people stopped itemizing
Before 2018 about three filers in ten itemized. The 2017 act roughly doubled the standard deduction and capped state and local taxes at $10,000 in the same stroke, and the share collapsed to under one in ten. The arithmetic is simple and unforgiving: itemizing is worth something only when the total beats the standard deduction, and then only on the excess. A household with $34,000 of itemized deductions against a $32,200 joint standard deduction has not saved the tax on $34,000 — it has saved the tax on $1,800. Every limit on this page is a reason the number you paid is larger than the number that counts, and the gap between them is usually what decides whether itemizing is worth the paperwork at all.
The cap that moved, and moves again
The SALT cap is the most volatile figure in this calculation. It was $10,000 flat from 2018, was raised to $40,000 for 2025 by the 2025 law, is $40,400 for 2026, rises about 1% a year through 2029, and then reverts to $10,000 in 2030 unless Congress acts again. Above $505,000 of income the 2026 cap is reduced by 30 cents on the dollar, though it never falls below $10,000 — which creates a band of income where an extra dollar earned costs more than a dollar in lost deduction. The practical consequence of the raise is that a band of filers who have taken the standard deduction since 2018 are worth re-checking: in high-tax states, property tax and state income tax alone can now clear the standard deduction without any other line at all.
Four limits, four different shapes
Each line on Schedule A is limited differently, and knowing which shape applies is most of the skill. SALT is a hard ceiling: anything above the cap is simply gone. Mortgage interest is prorated — on a balance above the acquisition-debt limit you keep the share the limit bears to the balance, so a $820,000 loan keeps about 91% of its interest — and only debt used to buy, build or substantially improve the home counts, so a cash-out portion spent elsewhere does not. Charitable gifts meet a floor from below and a ceiling from above: from 2026 only the aggregate above 0.5% of AGI is deductible, and cash gifts to public charities are capped at 60% of AGI, with anything over carried forward five years. Medical is the harshest floor of all at 7.5% of AGI, which is why it usually matters only in a year with a genuine catastrophe.
Bunching, and the new cap on value
The standard-deduction threshold rewards lumpiness. If your itemized total lands just under it every year, you get nothing every year; if you push two years of charitable giving and a January property-tax instalment into one December, you clear it comfortably in one year and take the standard deduction in the next. A donor-advised fund makes the charitable half of that manageable — the deduction lands in the bunched year while the money goes out to charities over time. One new limit runs the other way for the largest filers: from 2026 itemized deductions are cut by 2/37 of the lesser of the total or the taxable income above the 37% bracket, capping the benefit at 35 cents per dollar rather than 37. It reaches only top-bracket returns, but those are exactly the high-SALT, high-mortgage households for which the rest of this page matters most.
Frequently asked questions
Should I itemize at all?
Only if the total here beats your standard deduction — $16,100 single, $32,200 married filing jointly, $24,150 head of household for 2026. And only the amount ABOVE that is worth anything: a household $2,000 over the standard deduction gets the tax value of $2,000, not of the whole itemized total. Since 2018 most filers never clear it.
Why is my SALT deduction capped?
State and local income, sales and property taxes are deductible only up to a combined cap — $40,400 for 2026. The cap is temporary: it was raised by the 2025 law, rises about 1% a year through 2029, and reverts to $10,000 in 2030. Above $505,000 of income it is reduced by 30 cents per dollar, though never below $10,000.
Why is only part of my mortgage interest counted?
Interest is deductible on acquisition debt up to $750,000 — $1,000,000 for a mortgage taken out on or before 15 December 2017, which is grandfathered. On a larger balance you deduct the share of the interest that the limit bears to the balance, which is the shortcut the IRS itself allows. Interest on a cash-out portion not used to buy, build or improve the home does not count at all.
What is the new charitable floor?
From 2026 an itemizer deducts charitable contributions only above 0.5% of AGI. It applies to the aggregate of everything you gave, so it bites hardest on households that give a steady modest amount each year. Gifts above the 60%-of-AGI ceiling are not lost — they carry forward for up to five years.
What is the 2/37 cap?
New for 2026. Itemized deductions are reduced by 2/37 of the lesser of the itemized total or the taxable income sitting above the 37% bracket. In effect it caps the benefit of an itemized deduction at 35 cents per dollar instead of 37. It reaches only top-bracket filers, but for them it is exactly the high-SALT, high-mortgage households this page is for.
Can I make itemizing work in a year it otherwise would not?
Bunching is the standard move: put two years of charitable giving into one calendar year, or pay a January property-tax instalment in December, so one year clears the standard deduction comfortably and the other simply takes the standard amount. A donor-advised fund lets you take the deduction in the bunched year while giving the money out over time.