Percentage Increase or Decrease Calculator
🔢 Number, percentages & ratio. Use the Percentage increase or decrease (multiplier) formula to find new value, original value, percentage change: pick the value you want, type the others, and the answer updates as you go.
Use a negative percentage for a decrease: 20% off is a multiplier of 0.8.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| New value | no unit |
| Original value | no unit |
| Percentage change | % |
Worked example
Find the new value when Original value = 100, Percentage change = 20 %.
Using new = original × (1 + p/100): New value = 120.
Frequently asked questions
What is the formula for Percentage increase or decrease (multiplier)?
new = original × (1 + p/100). Use a negative percentage for a decrease: 20% off is a multiplier of 0.8.
What do the letters stand for, and what units are used?
New value, Original value, Percentage change in %.
How do you calculate new value?
Put the values into new = original × (1 + p/100). For example, with Original value = 100, Percentage change = 20 %, new value = 120.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (new value, original value, percentage change) and fill in the others: it rearranges the formula for you.
