Washington is 16% cheaper than Arlington.
When comparing Washington, DC and Arlington, VA, the overall cost of living indices are 171 and 203 respectively (national median = 100). Rent is $375/month cheaper in Washington, saving renters about $4,500/year.
Median household income is $33,873/year higher in Arlington. Home values also differ significantly — the median in Washington is $724,600 compared to $864,800 in Arlington.
Virginia has a lower income tax rate, making Arlington slightly more tax-friendly.
Washington vs Arlington — common questions
Other cost of living comparisons for Washington and Arlington