How itemized tax works on shared bills
Sales tax, meal tax, and alcohol tax are not flat fees. They scale with what you ordered. When a group splits tax evenly, someone is always overpaying — usually the person who ordered the least. Here’s how tax actually works across the US, and how to split it fairly.
Restaurant tax is three or four different taxes stacked into one line item: state sales tax, local sales tax, sometimes a separate meals tax, and sometimes a separate alcohol surtax. Each of these is a percentage of your subtotal, not a flat number — which means your share of the tax depends on how much you ordered, not how many people are at the table.
The layers of restaurant tax
State sales tax
Every state except five (Oregon, Montana, New Hampshire, Delaware, and Alaska) charges sales tax. Rates range from 2.9% (Colorado) to 7.25% (California). This applies to almost all restaurant food by default.
Local sales tax
Cities and counties add their own. New York City adds 4.5% on top of the 4% state tax, for a combined 8.875%. Seattle is 10.35% after local surcharges. Chicago’s combined restaurant tax can hit 10.75% once you add the city’s 0.5% restaurant tax and the Metro Pier surcharge.
Separate meals tax
Several states charge an additional, restaurant-only tax on top of general sales tax. Virginia, Massachusetts, Washington DC, Louisiana, and Rhode Island all do this. In Boston, for example, meals are taxed at 6.25% state plus 0.75% local, for 7% total — and then many diners add tip on top of the tax, which technically isn’t required.
Alcohol surtax
This is where even splits go wrong for groups with non-drinkers. Seventeen states tax alcohol at a different, usually higher rate than food. Washington State adds a 20.5% tax on spirits by the drink. In some counties of North Carolina and Georgia, liquor by the drink carries a 6–8% extra surcharge. In Hawaii, a general excise tax of 4.712% applies to everything, but alcohol often has local additional taxes layered on.
On most receipts, these are all collapsed into one line: TAX $11.36. That line is the sum of multiple rates applied to different subtotals.
Why even-splitting tax is almost always unfair
Say a table of four orders food and drinks. Alex gets a $14 salad. Bea gets a $26 entree. Cam gets $38 worth of food and beer. Dee gets $42 of food and three cocktails. The tax line at the bottom of the receipt says $11.36.
Even-splitting that tax means everyone pays $2.84 in tax. But Dee generated about 33% of the taxable subtotal ($42 out of $128). Dee’s fair share of the tax is $3.73. Alex generated 11% of the subtotal. Alex’s fair share is $1.25. The even split overcharges Alex by $1.59 and undercharges Dee by $0.89.
That’s a small number on one bill. On a group of eight with a $400 check over three drinks-heavy nights in a row, it adds up to real money.
The right way to split tax
Tax scales proportionally with the pre-tax subtotal. Here’s the formula:
Your share of tax = (your pre-tax subtotal / table’s pre-tax subtotal) × total tax on the bill
The same formula applies to tip, whether you’re tipping 18% or the mandatory 20% gratuity that gets auto-added for parties of 6+. Tip scales with what you ordered, not with the number of people at the table.
What about alcohol-specific tax?
If you’re in a state that taxes alcohol separately (Washington, North Carolina, Hawaii, etc.), and one or more people at the table didn’t drink, the fair thing to do is track the alcohol tax as its own line. Apply it only to drinkers. Apply the regular food tax proportionally to everyone based on what they ordered.
In practice, most receipts don’t itemize alcohol tax separately — it’s lumped into “TAX.” If the alcohol was a significant share of the bill and some people didn’t drink, it’s worth separating drinks into their own subtotal and calculating drinker-only tax on that portion.
Gratuity is not tax
A 20% auto-gratuity is not a tax. It’s an additional service charge that goes to the server. But it still gets split proportionally across the table based on pre-tax subtotal, the same way tip does. Don’t tip on top of auto-gratuity unless the service was exceptional.
How apps handle this
Any decent bill-splitting app does this math automatically. When each person at the table taps the items they ordered in splitmax, the app computes each person’s pre-tax share, then applies tax and tip proportionally. The whole table gets the right numbers without anyone having to do percentage math on their phone.
For the underlying logic of fair splits more broadly, see our guide on splitting restaurant bills fairly.