Many restaurant bills leave diners wondering whether gratuity should be based on the pre-tax subtotal or the final amount after tax. Both methods are easy to calculate, but local customs and restaurant policies vary.
Use the free Tip Calculator while following the examples below.
Tipping on the pre-tax subtotal
Using the subtotal keeps tax out of the gratuity calculation. Multiply the food and service subtotal by your chosen tip rate.
For a $100 subtotal and an 18% tip, the gratuity is $18. Add tax separately to find the final amount.
Tipping after tax
Some diners apply the percentage to the after-tax total because it is the most visible number on the receipt.
If an $100 subtotal becomes $108 after tax, an 18% tip on the after-tax amount is $19.44.
Check automatic gratuity and service charges
Restaurants may add gratuity for large groups or include a service charge. Read the receipt before adding another tip.
If the bill already includes gratuity, add an extra amount only when you intentionally want to reward exceptional service.
Practical checklist
- Work from an accurate original value or source file.
- Review the selected settings before processing.
- Check the result instead of assuming it is correct.
- Keep the original until the new result has been verified.
Frequently asked questions
Is tipping before tax wrong?
No. It is a common method and produces a transparent calculation based on the service subtotal.
Is a service charge always a tip?
Not necessarily. Ask the venue how the charge is distributed when the receipt is unclear.
How can I compare both methods?
Use the Tools2030 Tip Calculator and switch between before-tax and after-tax calculations.
Privacy: Tools2030 calculator inputs and supported file operations run locally in your browser unless a page clearly states otherwise.
Last reviewed: November 11, 2026.