Percentage Calculator

Overview

Handle percentage calculations, change rates, and ratios in one place. Just plug in numbers for common questions like 'What is B% of A?', 'What is the percentage change from A to B?', and 'A is what percent of B?' Faster than pulling up a calculator app when figuring out discounts or analyzing data.

Key Features

• Basic percentage (B% of A)
• Change rate (percentage change from A to B)
• Ratio (A is what % of B)
• Reverse calculation (find the original value from the result)
• Decimal place adjustment

How to Use

1. Select the calculation type: percentage, change rate, or ratio.
2. Enter numbers and the result appears in real time.
3. Adjust decimal places if needed.

Tips

• Discount price: subtract the discount % from the original. e.g., 20% off $50 = $50 - $10 = $40.
• Negative change rate means decrease, positive means increase. The sign tells you the direction.
• Works for tip calculations too. Calculate 10-15% of your meal total for the tip amount.

FAQ

What is the difference between change rate and ratio?

Change rate measures how much a value moved from the old to the new amount, while ratio measures what fraction one value is of another. For example, from 80 to 100 the change rate is +25%, and 80 is 80% of 100.

Are decimal results rounded?

By default, results are rounded to two decimal places. Change the precision setting to see more digits.

Can I enter negative numbers?

Yes, negative numbers are supported. The change rate calculation works correctly even when the old or new value is negative.