Calculate the Total Bill in Your Head

No one wants to whip out a calculator when the restaurant bill arrives. Whether you’re dining alone or with friends, calculating the total amount to lay down, including tax and tip, is not quite as easy as it seems.

Everything that follows assumes a 13% sales tax (e.g., Ontario’s HST) and a 15% tip (the conventional amount expected by servers).

The Trust Method: To calculate the total amount, including tax and tip, multiply the after-tax amount shown on the bill by 1.15. This method takes the restaurant’s word for the tax calculation, then adds a 15% tip. Some people can do that calculation in their head, but most need a calculator.

The Precise Method: If you don’t trust the restaurant’s tax calculation, multiply the before-tax amount by 1.13, then multiply the result by 1.15. Most people would want to use a calculator for this calculation.

Bill Sharing: The above gets a little more complicated if you’re sharing the bill, which is why some people prefer to split the total evenly amongst the diners. That’s not so difficult.

However, some people see this method as unfair, especially if they order less than the others. The easiest way to handle this is to ask the restaurant for separate checks. For some reason I don’t understand, though, most people won’t do this.

So if you want to split the bill fairly and the restaurant didn’t give you separate bills, add up the before-tax amounts for the items each person ordered, then use the precise method described above.

The Easy Way: For most people, the last calculation still requires a calculator, so let me show you an easy way to do this calculation in your head. First, as described above, add up the before-tax amounts for the items you ordered. Then add 1/3 to that total.

Example: If your before-tax total is $24, add $8 (1/3 of $24). $24 + $8 = $32. Lay down $32 and you’re done.

This is an approximation, but most people consider it close enough. The example above results in an overpayment of $0.81, a rather trivial amount that won’t break the bank. And the servers appreciate an overpayment more than an underpayment.

This method works when dining alone, too. Start with the before-tax subtotal shown on the bill, then add 1/3. Done!