Washington is 61% more expensive than Manchester.
When comparing Washington, DC and Manchester, NH, the overall cost of living indices are 171 and 106 respectively (national median = 100). Rent is $435/month cheaper in Manchester, saving renters about $5,220/year.
Median household income is $28,872/year higher in Washington. Home values also differ significantly — the median in Washington is $724,600 compared to $336,300 in Manchester.
New Hampshire has no state income tax, giving Manchester residents a significant tax advantage over District of Columbia's 10.75% rate.
Washington vs Manchester — common questions
Other cost of living comparisons for Washington and Manchester