Idaho and Washington at a glance
Idaho and Washington share a border, but a paycheck does not travel across it unchanged. A $60,000 salary leaves $28,084 a year after taxes and the four basics in Idaho and $22,876 in Washington.
Idaho comes out ahead by $5,207 a year ($434 a month). The calculation starts from the same gross pay in both states, subtracts federal tax, Social Security and Medicare, then each state's own income tax, and then the population-weighted cost of a one-bedroom rental, groceries, home energy and gasoline across 1,934,262 people in 44 counties in Idaho and 7,816,116 people in 39 counties in Washington.
Taxes: what each paycheck loses
Federal income tax ($5,072) and FICA ($4,590) on $60,000 are the same on both sides of the border. Washington does not tax wages, while Idaho takes $2,137 of a $60,000 salary in state income tax, so take-home pay is $2,137 higher in Washington.
At $100,000
At $100,000 take-home pay is $74,644 in Idaho and $78,901 in Washington, a difference of $4,257. The gap widens with income because graduated state brackets take a growing share.
Living costs
One-bedroom rent averages $1,132 a month in Idaho and $1,701 in Washington, so Idaho is $569 a month cheaper for housing. Food costs $3,436 a year in both, because the USDA Thrifty Food Plan is a national figure; home energy $1,553 and $1,732, and gasoline $1,549 and $1,883. Together the basics cost $20,118 a year in Idaho and $27,462 in Washington.
What the Census adds
Median household income is $77,800 in Idaho and $98,141 in Washington. Homeowners pay a median of $2,038 a year in property tax in Idaho and $4,556 in Washington. Commuters travel 21.6 minutes each way on average in Idaho and 26.6 in Washington.
Method
Taxes use the 2025 rules for a single filer with wage income only and the standard deduction. Housing and living costs are county figures from HUD (one-bedroom Fair Market Rent), the USDA Thrifty Food Plan and state energy prices from the Energy Information Administration, averaged across each state's counties and weighted by population, so large counties count more. Local income taxes are not included. Counties differ widely inside every state, so use the county pages for a specific place.