If you go out to eat at a restaurant in a foreign country, and you must pay a 15% service fee, followed by a 12% tax on everything, even the service fee, what actual exact percentage did you pay above the base price?

When faced with multiple percentage increases, it's a common mistake to simply add them together. However, because the second percentage is calculated on a new, higher amount, the actual total increase is greater than the sum of the percentages. In this scenario, the 15% service fee is applied to the base price of the meal. Then, the 12% tax is calculated not just on the original price, but on the price *after* the service fee has been added. This is a key detail that leads to the higher final percentage.

To understand the calculation, imagine a base price of $100 for simplicity. A 15% service fee would add $15, bringing the subtotal to $115. The 12% tax is then calculated on this $115, which comes out to $13.80. The final bill would be $128.80, representing a total increase of $28.80 from the original $100 price. This $28.80 is 28.80% of the initial cost, demonstrating the compounding effect of the successive percentages. This method of applying tax to service charges is a common practice in many parts of the world.

The distinction between a service charge and a tip is important in these situations. A service charge is a mandatory fee added by the establishment, whereas a tip is a voluntary gratuity left by the customer. Because service charges are considered part of the total sale, they are often subject to the same taxes as the food and beverages. This is why, in many countries with a Value Added Tax (VAT) or a similar consumption tax, you'll find that the tax is applied to the entire bill, including any obligatory service fees.