Percentage Calculator

How to Use the Percentage Calculator

Three modes available simultaneously: (1) What is X% of Y? (2) X is what % of Y? (3) % change from X to Y. All calculate live as you type.

Percentage Calculator Formula

Example Calculation

The Three Questions Percentages Answer

Almost every percentage problem is one of three questions in disguise. Once you can spot which one you are facing, the maths becomes trivial.

• What is X% of Y? Multiply: 15% of 800 = 0.15 × 800 = 120.
• X is what percent of Y? Divide and multiply by 100: 120 is what percent of 800? 120 ÷ 800 × 100 = 15%.
• X is Y% of what? Divide: 120 is 15% of what? 120 ÷ 0.15 = 800.

The calculator above handles all three, but recognising the pattern means you can sanity-check any result and do quick estimates in your head.

Increase, Decrease, and the Trap of Reversing Them

Percentage change measures how much a value has moved relative to where it started: (new − old) ÷ old × 100. A price rising from ₹100 to ₹120 is a 20% increase. The crucial trap is that percentage increases and decreases do not cancel out. If a ₹100 item rises 20% to ₹120 and then falls 20%, it does not return to ₹100 — it falls to ₹96, because the second 20% is taken from the larger ₹120. This is why a stock that drops 50% needs to gain 100%, not 50%, to recover. Keeping the base in mind prevents costly misreadings.

Percentage Points vs Percent

One of the most common errors in news and finance is confusing percentage points with percent. If an interest rate rises from 4% to 6%, that is an increase of 2 percentage points — but a 50% increase in relative terms (2 ÷ 4). Both statements are true and describe the same change, but they sound very different, and mixing them up can badly distort how big a change seems. When you read that something "rose 2%", check whether it means 2 percentage points or 2% of the original value — the difference is often large.

Everyday Uses

Percentages quietly run daily life: the GST added to a bill, the discount in a sale, the tip at a restaurant, the interest on a loan, a test score, a salary hike. A useful mental shortcut is that percentages are reversible — 8% of 50 is the same as 50% of 8, which is 4, and the second is far easier to compute. For anything that matters, though — a loan, a tax, a big discount — use the calculator to be sure, since a small percentage error on a large number is a large rupee error.

Frequently Asked Questions