How much is the sales tax if I buy an iPhone in Washington DC?

A quick internet search ("sales tax washington dc") indicates it's 6%.

If you do not live in the US, remember that warranty repairs/service for iPhonesmay not be available outside the country of purchase.

mastika wrote:

I wanted to buy iphone from Washington. How much the tax they charge? Thank you .

Contact the store and ask them. Every area in the US has different tax rates.