Quick summary
The calculator adds the numbers you enter. It does not guess an exact local tax rate or interpret a business policy.
Use the printed receipt rate and line items whenever they are available.
How calculations work
USTipCalc Methodology
USTipCalc uses simple receipt math. This page shows the inputs, formulas, and checks behind each result.
Core math
The calculator starts with the bill subtotal. It can subtract a discount, add tax, add a tip, add a business charge, and split the result.
Tip equals the selected basis times the tip percentage. Total equals subtotal minus discount plus tax, tip, and any added charge.
Tip basis and rounding
A pre-tax tip uses the subtotal before sales tax. A post-tax tip uses the amount after tax.
Rounding can change a total or a per-person share by a small amount. The result area shows the rounded amount.
State estimate limits
State pages use a statewide base rate and an average combined rate as planning inputs. They are not address-level restaurant rates.
County, city or town, transit authority, and local tax district rules can change the final amount. Use the receipt rate for a closer result.
How split bills work
An even split divides the final total equally. A custom split uses the shares you enter.
An itemized split assigns items to people and then allocates tax, tip, and a business charge by item value.
Learn more about the site
Example calculation checks
These examples check simple receipt math before release. They are not official tax examples.
| Case | Subtotal | Tax | Tip | Total | Per person |
|---|---|---|---|---|---|
| Basic 50 Pre Tax | $50 | $4.0 | $10.0 | $64.0 | $32.0 |
| Basic 50 Post Tax | $50 | $4.0 | $10.8 | $64.8 | $32.4 |
| Discount 100 Pre Tax | $100 | $6.4 | $16.0 | $102.4 | $51.2 |
| Service Charge 100 | $100 | $8.0 | $20.0 | $146.0 | $36.5 |
| No Tip Tax Only | $40 | $3.0 | $0.0 | $43.0 | $43.0 |
| Split 75 Three People | $75 | $6.0 | $15.0 | $96.0 | $32.0 |
Questions about USTipCalc Methodology
What is the basic tip formula?
Tip equals the selected tip basis multiplied by the tip percentage. For example, a 20% tip on a $50 pre-tax bill is $10.
Why does USTipCalc let users edit the tax rate?
Sales tax can vary by state, county, and city or town. In some locations, a transit authority or special-purpose tax district also affects the rate. The restaurant location and type of purchase can matter too. The rate shown on a receipt is usually the best input for a personal bill estimate.
How does itemized bill splitting work?
The itemized splitter assigns items to people, then allocates tax, tip, and service charge based on each person's share of the item subtotal.