How to use the automatic gratuity calculator
Enter pre-tip subtotal, gratuity already included, and desired total tip (%). Choose the currency for your inputs and read the result as you change the values.
How it works and formula
Additional tip = the greater of zero and (pre-tip subtotal × target rate − included gratuity).
Worked example
| Pre-tip subtotal | 80 |
|---|---|
| Gratuity already included | 12 |
| Desired total tip (%) | 20 |
Result
Additional tip $4.00
Try a second calculation
Start with the USD worked example above and change only gratuity already included to 16. Select Calculate. Your result should read:
Additional tip $0.00
Then enter 0 in the same field. Compare the result with the first scenario row. Holding every other input steady lets you see exactly how this one change affects the calculation.
Choosing your inputs
Read the receipt for a line explicitly described as gratuity. Enter the subtotal on which you want your target percentage calculated, then enter the amount already included. If the receipt calls it a service charge, ask how it is treated before counting it toward your target.
How to interpret the result
The result is the extra amount to write on the tip line. If the target is already met, leave the additional amount at zero. Adding the full target tip on top of the included amount would count part of your intended tip twice.
Frequently asked questions
What if the included gratuity already meets my target?
The additional tip is zero. The calculator does not reduce the charge already on your receipt.