Too many details to remember? We'll remember to broadcast important details to you to keep you current and avoid costly mistakes. Sales tax in NJ is just one of those many details you need to know. Last year (CY 2017), the tax rate was 6.875%; this year (CY2018), its down to 6.625%. Does that mean you have to compute it out to 3 decimal places? You bet it does! If you want the official source on this, visit the State of NJ, Department of the Treasury, Division on Taxation. Also remember that the IRS 2018 standard mileage rate has been increased to 54.5, up a penny from last year.