Date Calculator
Calculate the number of days between two dates or add and subtract days, weeks, months, and years.
Local processingPercentage Calculator
About this tool
Solve common percentage calculations, including finding a percentage of a number, increasing or decreasing a value, comparing the percentage change between two values, and finding an original amount from a discounted result.
Features
- Find a percentage of a number
- Increase or decrease a number by a percentage
- Calculate percentage change
- Find the original value before a discount
- Show the formula used
How to use
- Select problem type: Choose of, change, increase, decrease, or reverse.
- Enter values: Fill in percentages and amounts.
- Read answer: Copy numeric result and verify formula.
Examples
- Calculate sales tax
- Compare a value with the previous month
- Find the original price before a discount
- Calculate a restaurant tip
Limitations
- Money results may need to be rounded to the required number of decimal places
- Multiple successive percentage changes must be calculated in order
- The entered values and calculations are processed directly in your browser and are not sent to a server.
FAQ
- How is percent change calculated?
- ((new − old) / old) × 100, with sign indicating increase or decrease.
- Reverse percentage example?
- If 80 is the value after a 20% discount, the original value is 100.
- Can I chain discounts?
- Apply one discount at a time; multiple discounts must be calculated in order.