What is plus/minus percentage?
Plus/Minus Percentage refers to increasing or decreasing a value by a certain percentage.
- Vat calculation (+%) (e.g., "$100 product with a 10% vat becomes $110.").
- Value depreciation (-%) (e.g., "A $1000 laptop with 10% depreciation is now worth $900.").
About our plus/minus percentage calculator
Easily adjust values by any percentage with our Plus/Minus Percentage Calculator. Whether you're increasing a price, applying a discount, or projecting growth, our tool helps you quickly calculate values after adding or subtracting percentages.
On this calculator, you can:
Add a percentage to a number
Work with any scenario involving percent-based adjustments
Calculate tax, salary increase, discount, value depreciation or investment growth with confidence—our plus/minus percentage calculator does the work instantly and accurately.
Working the numbers step by step
Adding a percentage means multiplying by one plus the rate written as a decimal. The formula is New value = Original x (1 + P / 100). Take a $60,000 salary that gets a 10% raise: 10 / 100 gives 0.10, so the multiplier is 1.10, and 60,000 x 1.10 = $66,000. The $6,000 gain is exactly 10% of 60,000, which is a quick way to sanity-check the result.
Subtracting works the same way with a minus sign: New value = Original x (1 - P / 100). A $250 television with 15% off becomes 250 x (1 - 0.15) = 250 x 0.85 = $212.50. The $37.50 you save is 15% of the original price.
Common multipliers
| Percent | Add (+%) | Subtract (-%) |
|---|---|---|
| 5% | x 1.05 | x 0.95 |
| 10% | x 1.10 | x 0.90 |
| 15% | x 1.15 | x 0.85 |
| 20% | x 1.20 | x 0.80 |
| 25% | x 1.25 | x 0.75 |
| 50% | x 1.50 | x 0.50 |
Why -20% does not cancel +20%
Percentages apply to whatever value is in front of them at the moment, so a rise and an equal fall do not return you to the start. Begin with $100, add 20% and you get 100 x 1.20 = $120. Now take 20% off that $120: 120 x 0.80 = $96, not $100. The second 20% is measured against the larger $120, so it removes more dollars than the first one added. To land back on $100 after a 20% increase you would need to cut about 16.7% (1 / 1.20 = 0.8333).
Removing a percentage that is already baked in
If a $110 price already includes 10% VAT, you cannot recover the pre-tax figure by subtracting 10%. Taking 10% off $110 leaves $99, which is wrong. Because the tax was added by multiplying by 1.10, you reverse it by dividing: 110 / 1.10 = $100, and the VAT portion is the $10 difference. Use this whenever a total already contains the markup and you need the original base amount.
Frequently Asked Questions
1. How to plus percentage?
To add a percentage to a number (also known as increasing it by a percentage), follow this formula:
Formula:
Example:
- Investment growth - You invested $10,000 and it grew by 12%. What's the final amount?
- Salary Increase - You got a 10% raise on your $60,000 salary. What's your new salary?
2. How to minus percentage?
To subtract a percentage from a number (decrease it by a percentage), use this formula:
Formula:
Example:
- Product Discount - A $250 TV is on sale with 15% off. What's the new price?
- Value Depreciation - A car worth $30,000 loses 20% of its value. What's it worth now?