Sales Tax / VAT Calculator

Add sales tax or VAT to a net amount, or back the tax out of a tax-inclusive total — with up to two rate components that combine (for example a national rate plus a regional rate). All arithmetic is done in integer cents with big integers and half-up rounding, so the tax, net, and gross totals are exact to the cent and never drift from floating-point error. For inclusive totals, net plus tax always equals the gross you entered. Everything runs locally in your browser.