Washington is 80% more expensive than Arlington.
When comparing Washington, DC and Arlington, TX, the overall cost of living indices are 171 and 95 respectively (national median = 100). Rent is $511/month cheaper in Arlington, saving renters about $6,132/year.
Median household income is $32,768/year higher in Washington. Home values also differ significantly — the median in Washington is $724,600 compared to $276,400 in Arlington.
Texas has no state income tax, giving Arlington residents a significant tax advantage over District of Columbia's 10.75% rate.
Washington vs Arlington — common questions
Other cost of living comparisons for Washington and Arlington