How to Calculate a Tip and Split the Bill Fairly

Choose the tip base first

A pre-tax tip uses the food and service subtotal. An after-tax tip uses subtotal plus tax. Local habits differ, so consistency and transparency matter more than hiding the basis.

In the example, 20% of an $80 subtotal is $16. The $103 total includes $7 tax.

Equal split is not always equitable

An equal split works when orders are similar and shared items dominate. Large differences in individual orders may justify itemized shares.

One practical method is to assign individual items first, divide shared items, then allocate tax and tip in proportion to each person's subtotal.

• Agree on equal or itemized splitting before paying
• Keep tip percentage consistent across shares
• Handle coupons before calculating the tip base

Round only at the end

Rounding each intermediate share can create a total that no longer matches the bill. Calculate the full tip and total first, then round the final per-person amounts.

If the group deliberately rounds the total upward, treat the difference as additional tip and show it clearly.