Reverse Percentage Calculator - Calculate Original Value from Percentage
Help
The Original Value calculator (also known as reverse percentage calculator) helps you find the original value when you know a percentage and its result. This is useful for working backward from a known percentage to find the original amount.
Practical Uses
- Pre-Discount Price: If 25% [X] of the original price equals $50 [Z] discount, what was the original price? $200 [Y]
- Pre-Tax Amount: If 8% [X] tax equals $16 [Z], what was the pre-tax amount? $200 [Y]
- Original Value: If 15% [X] of a value equals 30 [Z], what is the original value? 200 [Y]
- Pre-Raise Salary: If a 10% [X] raise equals $5,000 [Z], what was the original salary? $50,000 [Y]
- Investment Principal: If a 12% [X] return equals $2,400 [Z], what was the original investment? $20,000 [Y]
- Total Budget: If 30% [X] of a budget equals $600 [Z], what is the total budget? $2,000 [Y]
How to Use
- Enter the percentage value in the first input.
- Enter the result amount that equals that percentage in the second input.
- The calculator instantly returns the original value; optional rounding is available.
- Click "Add to Memos" or press Enter to save the calculation.
How It Works
The Original Value calculator uses this formula:
Example: If 15% equals 30, the original value is:
So the original value is 200.
Need more percentage tools?
- Basic Percentage Calculator
For discounts or taxes. - Part-to-Whole Percentage
Find what % one number is of another. - Percentage Change Calculator
Work out increases or decreases. - Increased Value Calculator
Calculate value after percentage increase. - Decreased Value Calculator
Calculate value after percentage decrease. - Original Before Increase Calculator
Find original amount before percentage increase. - Original Before Decrease Calculator
Find original amount before percentage decrease. - Specialized Calculators (63+)
Practical everyday calculations for real-life scenarios.
Requirements and Important Information
- No installation required – works directly in your browser.
- Compatible with all modern browsers (Chrome, Firefox, Safari, Edge).
- Calculations are performed locally – no data is sent to any server.
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Your calculation memos is stored only on your device.
Each calculator stores up to 20 most recent calculations, automatically removing the oldest entries when this limit is reached. - Works offline after the initial page load.
- Supports both desktop and mobile devices.
- No account or login required.
Helpful Calculator Features
- Real-time calculations that update as you type.
- Copy results to clipboard with a single click.
- Calculation memos that persists between sessions.
- Option to round results for cleaner numbers.
- Clear visual formulas to understand the math.
- Mobile-friendly interface that works on all devices.
- Dark mode support for comfortable viewing.
- Keyboard shortcuts for faster calculations.
Tips for Accurate Calculations
- Double-check input numbers for accuracy.
- Use decimal points for precision.
- Calculations update instantly as you type.
- When the Round checkbox is checked, numbers are rounded to 2 decimal places.