Use the Discounted Bill Tip Calculator to compare tips on the original and reduced price, find a matching rate, and calculate tax and the final total.
Discounted Bill Tip Formula
A discount reduces the amount charged, but the tip can be calculated on either the original service value or the discounted subtotal.
Discounted subtotal:
Discounted Bill = Original Bill - Discount
Tip on the original bill:
Original-Base Tip = Original Bill * Tip Rate
Tip on the discounted bill:
Discounted-Base Tip = Discounted Bill * Tip Rate
Rate on the discounted bill that matches the original-base tip:
Matching Rate = Original-Base Tip / Discounted Bill
Variables:
- Original Bill is the price before a coupon, promotion, or comp
- Discount is either a dollar amount or Original Bill × Discount Percent
- Tip Rate is entered as a decimal in the formulas
- Matching Rate is the higher percentage needed on the discounted subtotal to preserve the same dollar tip
Sales tax in the calculator is applied to the discounted subtotal. The selected tip base affects only the tip amount, allowing you to compare the cost of recognizing the original service value with tipping only on the amount charged.
Discounted Bill Tip Reference Table
The table uses a $100 original bill and a 20% tip rate.
| Discount | Discounted bill | Tip on original | Tip after discount | Matching discounted rate |
|---|---|---|---|---|
| 0% | $100.00 | $20.00 | $20.00 | 20.00% |
| 10% | $90.00 | $20.00 | $18.00 | 22.22% |
| 20% | $80.00 | $20.00 | $16.00 | 25.00% |
| 30% | $70.00 | $20.00 | $14.00 | 28.57% |
Example Problems
Example 1: Compare tip bases after a coupon.
The original meal is $120 and a $30 coupon reduces the charged subtotal to $90. At 20%, the original-base tip is $24 and the discounted-base tip is $18.
Tipping on the original amount adds $6 compared with tipping the same rate on the discounted amount.
Example 2: Find the matching rate.
To leave the same $24 tip on the $90 discounted bill, divide $24 by $90.
The matching rate is 0.2667, or 26.67%. A 26.67% tip after the discount is approximately equal to 20% on the original $120 bill.
Frequently Asked Questions
Should I tip before or after a discount?
Many people tip on the original price when a discount does not reduce the work performed. The choice is personal and may depend on whether the discount reflects a promotion, a corrected charge, poor service, or an item that was removed entirely.
How do gift cards affect the tip base?
A gift card is a payment method rather than a price discount. In most cases, calculate the tip on the full eligible bill before subtracting the gift-card payment.
Does the calculator account for automatic gratuity?
No automatic gratuity is assumed. Check the receipt or contract and subtract any gratuity already included before deciding whether to add another tip.
