Basic Calculator · Practical guide
How to Calculate a Tip on a Calculator
Multiply the bill by the tip rate as a decimal, then add it back — the whole thing takes about five seconds.
At a glance
The Two-Step Method
To calculate a tip on any basic calculator, convert the percentage to a decimal and multiply. For a 20% tip on a $64 bill: 64 × 0.20 = 12.80, then 64 + 12.80 = 76.80 for the total. That is the entire trick — tip first, total second.
Interactive tool
Basic Calculator
Enter your own values, then compare the result with the examples below.
History (Last 10)
Tip Rates as Decimals
Divide any percentage by 100 to get its decimal form: 15% becomes 0.15, 18% becomes 0.18, and 20% becomes 0.20. Multiplying the bill by that decimal gives the tip amount directly.
| Bill | 15% Tip | 18% Tip | 20% Tip |
|---|---|---|---|
| $30.00 | $4.50 | $5.40 | $6.00 |
| $64.00 | $9.60 | $11.52 | $12.80 |
| $120.00 | $18.00 | $21.60 | $24.00 |
The 10% Shortcut
For a quick mental check, move the decimal point one place left to get 10% — $64 becomes $6.40. Double it for 20% ($12.80), or add half again for 15% ($9.60). You can verify any of these with the calculator above before you sign the receipt.
Splitting With a Tip Included
If four people share the $76.80 total, run 76.80 ÷ 4 = 19.20 so everyone pays $19.20. The history tape keeps each step visible in case the group wants to see the math.
Frequently Asked Questions
Is 15% or 20% a standard tip in the US?
For sit-down restaurants, 15-20% of the pre-tax bill is customary, with 20% common for good service. Counter service and takeout usually call for less.
Should I tip on the pre-tax or post-tax amount?
Etiquette guides generally say the pre-tax subtotal. On a $64 bill with $5 tax, tipping 20% on the subtotal is $12.80 instead of $13.80.
How do I calculate a tip without a percent button?
Convert the percentage to a decimal by dividing by 100, then multiply. 18% becomes 0.18, so 50 × 0.18 = 9.
How do I round a split bill fairly?
Calculate the exact share, then round each person's amount up to the nearest dollar. On a $19.20 share, four people paying $20 each also covers a little extra tip.