Percent or dollars
Pick Percent to tip a share of the bill, using the buttons or any percentage you type. Pick Dollars to leave a set amount; the calculator then tells you what percentage that comes to, so you can see whether $10 on a $64 bill is generous (it is about 15.6%).
Splitting the bill
Set how many people are paying, and each share is the total divided evenly, tip included. A share that does not come out to a whole cent is rounded up, and the few cents left over go to the server rather than going missing.
Before tax, and rounding
Open Tax and rounding to put in the tax shown on the receipt. The tip is then worked out on the bill before tax, which is the usual custom in the US, while the total still includes the tax. Rounding up the tip, or each person's share, to a whole dollar saves fumbling for change.
Questions
How much should I tip?
In US restaurants with table service, 15% to 20% of the bill before tax is the usual range, with 18% to 20% common for good service. Customs differ by country and by kind of service, and some bills already include a service charge, so check the receipt before adding a tip.
Is the tip worked out before or after tax?
On the whole bill, unless you put in the tax under Tax and rounding. Then it is worked out on the amount before tax.
Does it keep my bill?
No. Everything is worked out in this page, and nothing is stored or sent anywhere.