Tipping on the pre-tax subtotal and tipping on the post-tax total are both common, and this calculator lets you choose rather than deciding for you. Put the pre-tax subtotal in the bill field and the sales tax from your receipt in the tax field, then use the "Tip on" toggle. Subtotal applies your percentage to the pre-tax figure, which is the traditional etiquette position; Total incl. tax applies it to subtotal plus tax, which is what card terminals usually default to. The tax is owed either way, so it is always included in the total and in each person's share. On a $60 subtotal with $4.95 tax at 18%, tipping on the subtotal gives a $10.80 tip and a $75.75 total; tipping on the total gives $11.69 and $76.64. For how much that pre-tax-versus-post-tax choice adds up to across different sales-tax states, see our
pre-tax vs post-tax tipping study.