How to Calculate a Tip (Fast Mental Math + Splitting)

To calculate a tip, multiply the pre-tax bill by the tip percentage: a 20% tip on $50 is 50 × 0.20 = $10, for a $60 total. In the US, 15–20% is standard for sit-down service. Here's the quick mental math, splitting the bill, and a free tip calculator.

The fast mental-math trick

Find 10% by moving the decimal one place left ($50 → $5). Then: 20% = double it ($10), 15% = 10% plus half of 10% ($5 + $2.50 = $7.50), 18% ≈ halfway between. That covers almost every tip without an app. For exact amounts and splitting, use the Tip Calculator.

How much to tip (US)

• Restaurants (table service): 15–20%, more for great service.
• Bars: ~$1–2 per drink or 15–20% of the tab.
• Delivery: 10–15%, at least a couple of dollars.
• Taxi/rideshare: 10–15%.

Splitting the bill

Tipping for a group? Calculate the tip on the full pre-tax total, add it, then divide by the number of people — the Tip Calculator splits it evenly in one step. Tip on the pre-tax amount; tipping on tax is optional and slightly overpays.

Bottom line

Tip = bill × percentage; use the 10%-shortcut for quick math and 15–20% as your default. Calculate and split a tip free.