How to Calculate Percentage: The 3 Types Everyone Googles

Almost every "percentage" search is one of three questions. Once you can tell them apart, the math is easy — and a calculator makes it instant.

Type 1: What is X% of Y?

This is discounts, tips, tax and interest. The formula is simply (X ÷ 100) × Y. So 18% of 2,500 = 0.18 × 2,500 = 450. Skip the mental math with the percentage calculator, which handles all three types in one place.

Type 2: X is what percent of Y?

This is scores and shares: "37 out of 50 is what percent?" Divide and multiply by 100 — (37 ÷ 50) × 100 = 74%. For exam scores specifically, the exam marks percentage calculator also shows the grade band and works in reverse ("what do I need on the final?").

Type 3: Percentage increase or decrease

This is "prices went from 200 to 250 — by what percent?" The formula is ((new − old) ÷ old) × 100, so (250 − 200) ÷ 200 = 25% increase. The percentage change calculator does it both ways and is handy for salary hikes, price rises and growth metrics.

Where you'll actually use it

Shopping deals run through the discount calculator (final price after a percent off), and Indian invoices need the GST calculator to add or remove tax. Both are just percentage math with a friendlier interface.

A quick mental shortcut

Percentages are reversible: 8% of 50 equals 50% of 8 — and the second is obviously 4. Swapping the numbers often turns a hard percentage into an easy one you can do in your head.