Idaho vs Montana
On $100,000 these two come out level once cost of living is counted — which the tax rates alone would never tell you.
Property tax is set by counties, not states. Inside Texas alone the rate varies six times over, so this is the single choice that changes the answer most.
Does it work everywhere in Montana?
in what the money buys · $242 over 10 years
A pay cut of up to $35 (0.0%) still leaves you level.
Who worked this out, and what it is built on
I build and maintain every comparison on this site — 1275 state pairs so far, on the same engine that runs the tax calculators for all 50 states and 3,143 counties. This is not a template with two names swapped into it: Idaho and Montana are run through the actual rules of each place, and if the numbers say the move is not worth it, that is what the page says.
Four sources, and one deliberate refusal. Federal figures from the IRS revenue procedure. State rates read one state at a time off each state’s own department of revenue. County property tax from the US Census Bureau. Cost of living from the Bureau of Economic Analysis Regional Price Parities, 2024 — and not from Numbeo or any other crowd-sourced index, because those are filled in by users, publish no methodology, and cannot be cited. That single choice is most of why the cost-of-living numbers here differ from everybody else’s.
When I get something wrong I publish the correction with the date and what it cost — including the two mistakes on these pages I found myself. Data last verified September 1, 2026.
Where to go from here
Almost nobody is choosing between exactly two places. These are the questions that usually come next, with the answer already attached so you can see which is worth opening.
Other moves involving Idaho or Montana
States that sit near Montana on prices compared against Idaho, and the mirror of that. The comparison you would run next.
- Idaho vs North Carolina— North Carolina by $1,217
- Idaho vs Wisconsin— Idaho by $2,309
- Idaho vs South Carolina— South Carolina by $2,041
- Michigan vs Montana— Montana by $2,731
- Georgia vs Montana— Montana by $2,205
- Montana vs North Carolina— North Carolina by $1,193
Each state on its own
The full detail behind each half of the comparison above.
The counties that decide it
Property tax is set by county, and the spread inside one state beats most state pairs.
- Clark County, Idaho— 0.29%, the cheapest
- Nez Perce County, Idaho— 0.87%, the dearest
- Madison County, Montana— 0.41%, the cheapest
- Blaine County, Montana— 1.52%, the dearest
Similar in price to Idaho
States that sit next to Idaho on the price index — often the comparison people should have run.
- Maine— 97 on prices
- Georgia— 96.3 on prices
- Michigan— 96.2 on prices
- North Carolina— 94.3 on prices
- Every Idaho comparison— all 50
- Every Montana comparison— all 50
- The nine states with no income tax— and what they charge instead
On $100,000, Idaho and Montana come out level — and the rates are nothing like level
Two states that finish in a dead heat on a measure built out of five taxes and a price index is not a boring result; it means several large differences are cancelling. On $100,000 with a $400,000 home the purchasing power is $76,145 in Idaho and $76,170 in Montana — $24 apart, which on this salary is noise.
The parts are not level at all. State income tax is $4,447 against $4,289, property tax $2,014 against $2,834, and the price index 95.5 against 94.6. Any one of those quoted alone would look like a decisive argument for one side. Together they come to nothing, which means for this pair the money is genuinely not the deciding factor and you can choose on everything else.
Where the two sit nationally: Idaho is the 29th most expensive place to live of the 51 — the 50 states and the District of Columbia — and Montana is 30th. Housing, the component that moves most, is 90 against 84.6.
Grey columns are what a year of Idaho and a year of Montana are worth in the same money. The bars between them are each thing that changes, in the order it changes: green adds, amber takes away.
Where the money actually goes, line by line
Five separate taxes, and on this pair property tax is the biggest single difference — $820 against $158 for the income tax everybody quotes:
Federal income tax — $13,170 either way. Identical, because it is federal. Any comparison that shows a difference here is wrong.
FICA — $7,650 either way. Also federal, also identical.
State income tax — $4,447 in Idaho, $4,289 in Montana. A difference of $158.
Property tax — $2,014 in Idaho, $2,834 in Montana on a $400,000 home, at each state's median local rate. This is bigger than the income tax difference, and it runs the other way — which is the whole reason the headline number disappoints.
Local income tax — zero on both sides. Both Idaho and Montana keep income tax at the state level only, so the figures above are complete rather than approximations.
Total: $27,281 in Idaho against $27,944 in Montana — 27.3% and 27.9% of gross.
And Idaho housing costs 6.4% more
These two states cost almost the same to live in, which is why the tax difference survives into the answer. The index is the Bureau of Economic Analysis Regional Price Parity — official, published per state, 100 is the national average — and it is worth looking at the components even when the headline barely moves, because they can disagree with it.
Cheaper in Montana than IdahoDearer in Montana than Idaho
Each bar is how far apart Idaho and Montana are on that component, and which way. Housing almost always runs several times wider than everything else — which is why a single blended index tells you very little.
All items — 95.5 in Idaho, 94.6 in Montana. A gap of 0.9 points.
Housing — 90 against 84.6. A gap of 5.4 points, 6.0× the headline gap. This is what people mean when they say somewhere is expensive.
Goods — 96.3 against 96, 0.3 points apart — 18.0 times narrower than the housing gap — and typical: across all 1,275 pairs the median is 2.7 points for goods against 24.9 for housing. Blended into one figure, what you are reading is mostly housing wearing a general label.
Utilities — 70.4 against 72.3. 1.9 points apart, close enough not to change a decision.
Which half of this reaches you depends on whether you buy. Renting, the real difference between Idaho and Montana is $911 a year — property tax comes out of your side entirely, and what is left is the price level. Buying a $400,000 home it is $24. So renting is where the gap is widest here, by $887 — unusual, and it means buying erodes the advantage rather than compounding it.
The number to take into a salary negotiation: $99,965
This is the question people are actually asking and almost nobody answers: what would I need to earn in Montana to live exactly as well as I do on $100,000 in Idaho?
$99,965. That is 0.0% less than you earn now. You could take a pay cut of $35 moving to Montana and be no worse off — which is a very different conversation to have with a recruiter than "Montana has lower taxes".
The dashed line is the salary you earn now. The solid line is what matches it in Montana. If the relationship were a simple multiplier the two would be parallel — they are not, because brackets, the Social Security ceiling and a property tax that does not move with income all bend it.
The obvious shortcut fails here, and by a measurable amount. Scaling your salary by the ratio of price levels — $100,000 × 94.6/95.5 — gives $99,058. The answer is $99,965, so the shortcut is $907 too low: brackets, the Social Security ceiling and a property tax that ignores income all bend the line the shortcut assumes is straight.
The figure belongs to the two states and your income. On $40,000 the match in Montana is $40,508, 1.3% above what you earn; on $250,000 it is $249,328, 0.3% below. The relationship bends by 1.5% across that range.
Over 10 years: $242
Ten years of a difference this small is still a small number: $242. Which is the point — on a horizon long enough for compounding to matter, this pair still does not separate on money.
At $24 a year of real difference, 10 years in Idaho instead of Montana is worth $242 in today's purchasing power — before compounding anything you might invest it in.
The line starts below zero because moving costs about $15,000 and lands entirely in year one. It pays for itself inside the first year. That is the figure a per-year comparison hides.
And it is slower to arrive than the annual figure suggests. Reckoning $15,000 for removal, fees and the cost of selling — an assumption this page makes, not a figure from a source — at $24 a year it takes 619.4 years to recover — so the annual figure only becomes yours from year 621.
At three horizons: $73 over three years, $242 over 10, $727 over thirty — and the three-year figure does not clear the cost of getting there.
None of those figures contains the one variable that could overturn them: the same job rarely pays the same in Idaho and Montana. That is what the $99,965 break-even above is for — it prices an offer instead of assuming the offer is identical.
Choosing the county matters more than choosing the state here
This comparison is worth $24 a year. Choosing where inside Idaho to live is worth $2,306 a year on the same $400,000 home — 95.2 times as much.
Idaho has 44 counties and the effective property tax rate runs from 0.29% in Clark County to 0.87% in Nez Perce County. Move to the wrong county in the better state and you have given back more than the move gained you, twice over.
Which reframes the question. Rather than "Idaho or Montana", the decision that carries the money is which county inside Idaho — and the answer is not visible on any comparison that stops at the state line. Set both in the calculator above and every figure on this page recomputes on your actual rates rather than two medians.
The same logic applies to the losing side: Montana has counties cheaper than the median used here too, and for a reader who is staying put, moving county at home may be the better version of this decision.
You could take a $35 pay cut to move to Montana and be no worse off
That is the version of this comparison worth taking into a negotiation, and it is not a figure any tax calculator produces.
Matching your $100,000 standard of living in Idaho takes $99,965 in Montana — 0.0% less than you earn now. So an offer of $99,965 is not a downgrade, and an offer above it is a raise however it looks on paper.
The reverse framing is the one recruiters use, and it is worth being able to answer: a company in Idaho offering to match your current salary is offering you less than the Montana job at $99,965. On 10 years the difference is $242.
Where every number here comes from
Four sources, each read off the body that publishes it:
US Bureau of Economic Analysis — Regional Price Parities by State and Metro Area, 2024 (released 19 February 2026) — read 2026-09-08. https://www.bea.gov/data/prices-inflation/regional-price-parities-state-and-metro-area
IRS — Revenue Procedure for the tax year (federal brackets, standard deduction and FICA) — read 2026-09-02. https://www.irs.gov/
Each state's own department of revenue (state income tax rates and deductions), verified one state at a time — read 2026-09-02. https://estimatetax.net/sources/
US Census Bureau, American Community Survey (county effective property tax rates) — read 2026-08-31. https://data.census.gov/
The cost of living index is the part worth checking, because it is where comparison sites usually reach for something crowd-sourced. The Regional Price Parities are produced by the Bureau of Economic Analysis, cover every state and metro area, and are published with a methodology document. The figures here are the 2024 release and are not extrapolated forward.
And what this page does not model:
— The cost of living index is the BEA's Regional Price Parity for 2024, the most recent published. It is not extrapolated to the current year, and it is a state-wide average — inside a state, a metro area and a rural county differ by more than most state pairs do.
— Moving costs, state transfer taxes on buying a home, and the cost of selling the one you have are not included. On a short stay they can outweigh every annual difference on this page.
— Sales tax is not modelled. It is inside the BEA index — that is what a price parity measures — but it is not broken out separately here.
— The comparison assumes the same salary in both places unless you change it. In practice a job in a high-cost state usually pays more, which is exactly what the break-even figure is for.
— Health insurance, childcare and car insurance vary enormously by state and are only inside the index as averages. If any of the three is a large part of your budget, it deserves its own arithmetic.
Where to go next
Questions
- Is it cheaper to live in Idaho or Montana?
- On $100,000 they come out level — $76,145 of purchasing power in Idaho against $76,170 in Montana, a difference of $24 a year. That is unusual and worth knowing, because the headline rates are not level at all: state income tax is $4,447 against $4,289 and property tax $2,014 against $2,834. They cancel out.
- How much do I need to earn in Montana to match $100,000 in Idaho?
- $99,965 — 0.0% less than you earn now, so a pay cut of up to $35 still leaves you level. That accounts for federal tax, FICA, state tax, property tax and the price level in each state.
- What are the taxes in Idaho vs Montana?
- On $100,000: state income tax of $4,447 in Idaho against $4,289 in Montana, and property tax of $2,014 against $2,834 on a $400,000 home at median county rates. Federal tax and FICA are identical in both — $13,170 and $7,650 — so any comparison showing a difference there is wrong.
- Does Montana really have lower property tax?
- That depends entirely on the county, which is why a state-level answer is not much use. Montana runs from 0.41% in Madison County to 1.52% in Blaine County — 3.7 times, or $4,454 a year on a $400,000 home. The median is 0.71%.
- How much is the difference over 10 years?
- $242 in today's purchasing power, at $24 a year. That excludes moving and housing transaction costs, which land in year one and can outweigh everything else on a short stay.
- Where does your cost of living data come from?
- The Bureau of Economic Analysis Regional Price Parities for 2024, an official index covering every state and metro area with a published methodology. Not a crowd-sourced database — and it comes broken into housing, goods, utilities and services, which matters because housing moves several times more than anything else.