A tip calculation is really two calculations
First, the tip amount is Bill × Tip Percentage ÷ 100. Then the final bill is the original amount plus that tip. When a group is splitting the check, both totals can be divided by the number of people so everyone sees the same basis.
Toolmera keeps the full tip, full total, tip per person and total per person visible together. That makes it easier to catch a mistaken percentage or head count before anyone pays.
Tip amountBill × tip % ÷ 100
Final totalBill + tip
Per personFinal total ÷ number of people
Preset percentages are shortcuts, not etiquette advice
The quick percentage buttons are there to save typing. They are not a recommendation about what you should tip, because tipping customs vary by country, venue, service type and sometimes by whether a service charge is already included.
If the bill already includes a mandatory service charge, decide whether an additional tip is appropriate before applying another percentage.
The calculator is currency-agnostic
There is no exchange-rate logic in a tip calculation. Enter the bill in dollars, euros, pounds, rupees or another currency and the result stays in that same unit.
The only requirement is consistency: the bill and the amounts you interpret from the result should all use the same currency.