Idaho vs Washington
A tax calculator says the difference is $3,316 a year. Once you count what a dollar actually buys in each, Idaho is $5,085 ahead — $50,849 over 10 years.
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 Washington?
in what the money buys · $50,849 over 10 years
You need 7.7% more for the move to break even.
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 Washington 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 Washington
States that sit near Washington on prices compared against Idaho, and the mirror of that. The comparison you would run next.
- Idaho vs New York— Idaho by $15,367
- Idaho vs Massachusetts— Idaho by $10,023
- Idaho vs New Jersey— Idaho by $15,316
- Michigan vs Washington— Michigan by $2,378
- Georgia vs Washington— Georgia by $2,904
- Montana vs Washington— Montana by $5,109
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
- San Juan County, Washington— 0.57%, the cheapest
- Pierce County, Washington— 0.94%, 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
- Montana— 94.6 on prices
- Every Idaho comparison— all 50
- Every Washington comparison— all 50
- The nine states with no income tax— and what they charge instead
A tax calculator says Washington. The right answer is Idaho, by $5,085 a year
This is one of the 324 state pairs out of 1,275 where the two answers point at different states, and it is worth understanding why before trusting any comparison of these two. On $100,000 with a $400,000 home, Washington leaves you $3,316 more in take-home. That figure is correct. It is also the wrong basis for the decision.
Because Washington is the more expensive place to spend it. On the Bureau of Economic Analysis price index Idaho is 95.5 and Washington is 107, national average 100. Deflate each take-home by where it gets spent and the ranking inverts: $76,145 in Idaho against $71,061 in Washington. Idaho wins by $5,085 a year — the opposite state to the one the tax figure names, and $50,849 over 10 years.
Where the two sit nationally: Washington is the 6th most expensive place to live of the 51 — the 50 states and the District of Columbia — and Idaho is 29th. Housing, the component that moves most, is 90 against 126.
Grey columns are what a year of Idaho and a year of Washington 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.
Why the two answers disagree, and which one to use
It is worth being precise about what is happening here, because "the cost of living is higher" is the kind of phrase that gets used to wave away an inconvenient number, and this is not that.
Both figures are correct measurements of different things. Take-home answers: how many dollars land in your account? Washington wins that, by $3,316. Purchasing power answers: how much can those dollars buy where you will be spending them? Idaho wins that, by $5,085. The second question is the one you are actually asking when you ask where to live.
The mechanism is arithmetic rather than opinion. Divide the Washington take-home by its price level and you get $71,061; do the same in Idaho and you get $76,145. The whole reversal comes from a price index of 95.5 against 107, published by the Bureau of Economic Analysis for exactly this purpose.
Where the nominal figure is the right one to use: if you are working in one state and spending in another — a border commute, a remote job you will leave, a posting you will not settle in — then your costs do not follow the state you are paid in, and take-home is what matters. That is a real case and it is why both numbers appear on this page rather than only the one that supports the conclusion.
Where the money actually goes, line by line
Five separate taxes, and here they matter but they do not win: the price level shifts the answer by $8,557 against $4,447 for the biggest tax gap. Both are in play, which makes this one of the pairs where the layers are worth reading closely:
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, $0 in Washington. Washington does not levy one at all, which is the fact that sells the move — and, as the next line shows, not the fact that decides it.
Property tax — $2,014 in Idaho, $3,145 in Washington on a $400,000 home, at each state's median local rate. Smaller than the income tax gap here, which is not usually the case.
Local income tax — zero on both sides. Washington has none at any level, state or local — and that holds for all nine states without a state income tax, none of which lets a county or city levy one either. The two go together.
Total: $27,281 in Idaho against $23,965 in Washington — 27.3% and 24.0% of gross.
And Washington housing costs 40.0% more
The cost of living gap between Idaho and Washington is almost entirely a housing gap, and that is only visible because the Bureau of Economic Analysis Regional Price Parity publishes its components separately rather than as one blended number. 100 is the national average.
Cheaper in Washington than IdahoDearer in Washington than Idaho
Each bar is how far apart Idaho and Washington 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, 107 in Washington. A gap of 11.5 points.
Housing — 90 against 126. A gap of 36.0 points, 3.1× the headline gap. This is what people mean when they say somewhere is expensive.
Goods — 96.3 against 104.4, 8.1 points apart — 4.4 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 92.9. 22.5 points, the second widest component after housing on this pair, and large enough to matter to anyone heating or cooling a big house.
Which half of this reaches you depends on whether you buy. Renting, the real difference between Idaho and Washington is $4,255 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 $5,085. So buying widens the gap by $830: the more house you own, the more this comparison is worth to you.
The number to take into a salary negotiation: $107,734
This is the question people are actually asking and almost nobody answers: what would I need to earn in Washington to live exactly as well as I do on $100,000 in Idaho?
$107,734. That is 7.7% more than you earn now. Anything less than $107,734 and the move costs you money however it is presented.
The dashed line is the salary you earn now. The solid line is what matches it in Washington. 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 × 107/95.5 — gives $112,042. The answer is $107,734, so the shortcut is $4,308 too high: 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 Washington is $44,483, 11.2% above what you earn; on $250,000 it is $263,796, 5.5% above. The relationship bends by 5.7% across that range.
"Idaho" and "Washington" are not places you can compare
Every figure above uses each state's median local property tax rate — its counties in Idaho, its counties in Washington — and that is a simplification the page should own rather than hide.
Washington has 39 counties, and the effective property tax rate runs from 0.57% in San Juan County to 0.94% in Pierce County — 1.7 times. On a $400,000 home that is a spread of $1,487 a year, without leaving the state.
44 counties. Each dot is one. The spread is 3.0 times from end to end, which is why a state average is not a number you can plan with.
Idaho has 44 counties, and the effective property tax rate runs from 0.29% in Clark County to 0.87% in Nez Perce County — 3.0 times. On a $400,000 home that is a spread of $2,306 a year, without leaving the state.
So the honest version of this question is not "Idaho or Washington" but which county. Picking the cheapest county in Washington against the dearest county in Idaho swings the property tax line by $1,198 a year; the reverse choice swings it $2,595 the other way. Against a headline difference of $5,085, the county is not a detail — it is most of the decision.
Neither Idaho nor Washington lets its counties levy their own income tax, so that layer is genuinely zero here rather than unmodelled — one of the 1,225 pairs out of 1,275 where it does not apply. It is the reason Idaho and Washington are easier to compare honestly than most neighbours are.
Over 10 years: $50,849
Nobody moves for one year, and almost no comparison prices the decision over the horizon on which it is actually made.
At $5,085 a year of real difference, 10 years in Idaho instead of Washington is worth $50,849 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 takes until year 3 for the move to pay for itself. That is the figure a per-year comparison hides.
The first slice of it is not yours, though. Reckoning $15,000 for removal, fees and selling costs — this page's assumption, not a sourced figure — at $5,085 a year it takes 2.9 years to earn back, so a stay shorter than that loses money on a move the annual figure calls a win.
At three horizons: $15,255 over three years, $50,849 over 10, $152,547 over thirty.
None of those figures contains the one variable that could overturn them: the same job rarely pays the same in Idaho and Washington. That is what the $107,734 break-even above is for — it prices an offer instead of assuming the offer is identical.
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 Washington?
- Idaho, by $5,085 a year in real purchasing power on $100,000 with a $400,000 home. The take-home difference is only $3,316; the rest comes from the cost of living, where Idaho indexes at 95.5 and Washington at 107 against a national average of 100.
- How much do I need to earn in Washington to match $100,000 in Idaho?
- $107,734 — 7.7% more. That accounts for federal tax, FICA, state tax, property tax and the price level in each state.
- What are the taxes in Idaho vs Washington?
- On $100,000: state income tax of $4,447 in Idaho against $0 in Washington, and property tax of $2,014 against $3,145 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 Washington really have lower property tax?
- That depends entirely on the county, which is why a state-level answer is not much use. Washington runs from 0.57% in San Juan County to 0.94% in Pierce County — 1.7 times, or $1,487 a year on a $400,000 home. The median is 0.79%.
- How much is the difference over 10 years?
- $50,849 in today's purchasing power, at $5,085 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.