Percentage & Tip Calculator

What this calculator handles

Three everyday math jobs live in one place here: finding a plain percentage (what is 15% of 80?), working out percent change between two numbers (a price went from $50 to $65 — how much of a jump is that?), and splitting a restaurant bill with tip across a table of friends. They sound different but they all lean on the same idea — a part measured against a whole — so it made sense to keep them together.

A quick worked example

Say dinner comes to $84.50 and you want to leave 20%. The tip is 84.50 × 0.20 = $16.90, making the total $101.40. Split four ways, that's $25.35 each. For percent change, the formula is (new − old) ÷ old × 100. Going from 50 to 65 is (65 − 50) ÷ 50 = 0.30, or a 30% increase. One common gotcha: a 50% drop followed by a 50% rise does not bring you back to where you started — $100 falls to $50, then rises to $75. Percent changes always measure against the newer starting point.

Tipping notes for the U.S.

In American restaurants 18–20% on the pre-tax total is the usual sit-down range, 15% for lighter service, and a flat couple of dollars for counter or coffee orders. Some people tip on the total including tax, which is a slightly more generous habit — both are fine, and this tool lets you pick your percentage either way.

How to use it

1. Choose the mode you need: percentage of a number, percent change, or tip & split.
2. Type your figures — the bill amount and tip percent, or the two numbers you're comparing.
3. For tips, set how many people are sharing the check to see the per-person amount.
4. Read the result instantly; adjust any field and it recalculates as you type.

FAQ

Should I tip on the total before or after tax?

Either is acceptable. Tipping on the pre-tax subtotal is standard; tipping on the post-tax total leaves a little extra. Enter whichever amount matches your preference.

Do my numbers get sent anywhere?

No. Every calculation runs inside your browser, so nothing you type is uploaded or stored.

Why doesn't a 20% raise cancel a 20% cut?

Because each percentage is taken from a different base. A 20% cut on 100 gives 80, and a 20% raise on 80 gives 96 — not back to 100.

Is it free?

Yes, it's free and supported by ads on the page. Results are estimates for quick reference, not financial advice.