How do I find the original price before a discount?

Divide the discounted price by one minus the percentage off. An item at $68 that was 20 percent off sits at 80 percent of its original price, so $68 divided by 0.80 is $85. Multiplying $68 by 1.25 gives the wrong answer, because you are working backwards rather than forwards.

What is the difference between percentage change and percentage points?

Percentage points describe the arithmetic gap between two percentages; percentage change describes the relative movement. A rate rising from 5 percent to 8 percent is a rise of 3 percentage points but an increase of 60 percent in relative terms. Mixing the two is how reports make small shifts sound enormous.

Why do successive percentages not simply add up?

Because each one applies to a new base. A 10 percent rise followed by a 10 percent fall returns less than you started: 100 becomes 110, then 99. Multiplying the factors — 1.10 times 0.90 — gives 0.99, which is the correct way to combine rates.

How do I work out what percent A is of B?

Divide A by B and multiply by 100. What percent is 45 of 60? 45 divided by 60 is 0.75, so 75 percent. The order matters: dividing the wrong way round is the single most common mistake in percentage work.

Calculate Percentages and Discounts

Percentage calculations come up constantly — discounts at the store, tips at restaurants, tax amounts, grade scores, business growth rates. Getting the math wrong costs real money. Here is how to do it correctly.

The Three Common Calculations

Finding X% of a number: Multiply the number by the percentage divided by 100. Example: 15% of 200 = 200 × 0.15 = 30. Finding what percent A is of B: Divide A by B, then multiply by 100. Example: 45 is what % of 180? = (45/180) × 100 = 25%. Percentage change: (New − Old) / Old × 100. Example: Sales went from 80 to 120 = (120−80)/80 × 100 = 50% increase.

Real-World Examples

A shirt costs $45 and is 30% off. Discount: $45 × 0.30 = $13.50. You pay $31.50. Your restaurant bill is $67 and you want to leave 18% tip. Tip: $67 × 0.18 = $12.06. Total: $79.06. Your website traffic went from 1,200 to 1,560 visitors. Growth: (1560−1200)/1200 × 100 = 30% increase.

One more percentage people calculate every month: health insurance as a share of income. The 2026 average marketplace premium of $462/month is about 11% of a $50,000 salary — and after subsidies closer to 4%. Shift Ledger's guide to health insurance cost as a percent of income and hours of work works the numbers in both dollars and hours.

Doing one of those repeatedly? The Tip Calculator splits the bill and the tip across a group, and the US Sales Tax Calculator works the tax rate backwards out of a total when the shelf label does not show it.

What I Tested

I used the Percentage Calculator with several scenarios.

• What is 25% of 360? → 90. Correct.

• 45 is what percent of 180? → 25%. Correct.

• Percentage change from 200 to 260? → 30% increase. Correct.

• Percentage change from 500 to 420? → 16% decrease. Correct.

The calculator handles all three types and updates results instantly.

Step-by-Step

(1) Open the Percentage Calculator. (2) Select the calculation type (find %, what %, or % change). (3) Enter your numbers. (4) Read the result instantly.

How It Compares

Calculator.net has a percentage calculator but has a cluttered interface with ads. Google Search calculates simple percentages (search '25% of 200') but only handles one calculation at a time. Our tool handles all three percentage calculation types with a clean interface and instant results.

Limitation

The calculator rounds results to two decimal places. For financial calculations requiring more precision, use a spreadsheet application like Excel or Google Sheets.

Common Mistake

Calculating percentage change in the wrong direction. Going from 100 to 150 is a 50% increase. Going from 150 to 100 is a 33.3% decrease — not 50%. The base (starting value) matters. Our calculator handles this correctly by using the starting value as the denominator.

Privacy: Every percentage is worked out on your device — enter the numbers, get the answer, and know that the figures you typed are not stored or transmitted anywhere.

Next Step: For more complex financial calculations, try the Loan Calculator for EMI, interest, and payment schedules.

Reverse Percentages: Getting Back to the Original Number

Sale price, mark-up, tax-inclusive totals and statistics that quote a figure after growth all hide the number you actually want. The rule is the same in every case: divide by the factor that was applied. A price after 15 percent off is 85 percent of the original, so the original is the sale price divided by 0.85. A figure that grew by 12 percent is 112 percent of what it started at, so the starting value is the current figure divided by 1.12.

Two everyday examples settle it. A jacket at $101.99 after a 15 percent discount was $119.99 before it. A town whose population of 8,400 is up 20 percent from last year had 7,000 residents then. Notice both work because the percentage is converted to a decimal first — 15 percent becomes 0.15, and the divisor is one minus or plus that number.

Compound Percentages and Chained Changes

Numbers that move twice do not move additively. A product that falls 10 percent and then rises 10 percent is worth 99 percent of its starting price, not 100 — the rise applies to the smaller number. Discount codes stack the same way: 20 percent off followed by a further 10 percent off leaves you paying 72 percent of the original, not 70.

To chain any sequence, multiply the factors together: 0.90 times 1.10 equals 0.99 for the example above. For rates in a spreadsheet, use the product of the individual changes rather than their sum, and label the result as a relative change so nobody reads it as a percentage-point movement.