Percent Increase Calculator
Calculate the percentage increase between two values, or find the increased or original value from a percent increase
By Waqar Mushtaq · Last updated:
A percent increase expresses how much a value has grown as a share of where it started -- "rent went up 8%," "sales grew 150%," "a 20% markup." This calculator answers all three questions that come up with an increase: how big was the rise (given the before and after values), what's the new value after a given percent increase (given the original value and the percentage), and what the value was before a known percent increase (given the increased value and the percentage, like backing a price out of a total). Every result also shows the multiplier, the percent decrease that would undo the increase, and a table of the same starting value at common percent increases -- because a 100% increase is undone by a 50% decrease, not a 100% one.
How Percent Increase Is Calculated
O(1) calculationV_original = starting value · V_new = value after the increase
p = percent increase as a decimal (25% = 0.25)
Percent decrease needed to return from V_new to V_original
Subtract the original value from the new value to get the amount of the increase, divide by the original value, and multiply by 100. Dividing by the new value instead is the most common mistake -- it gives the percent you'd have to cut to get back, not the percent increase.
Example -- find the percent increase: a price rises from $50 to $65. (65 − 50) / 50 × 100 = 15 / 50 × 100 = 30% increase
Example -- find the value after an increase: raise $200 by 15%. 200 × (1 + 0.15) = 200 × 1.15 = $230
Example -- find the original value: a bill is $138 after a 20% increase. 138 / (1 + 0.20) = 138 / 1.20 = $115 -- not $138 × 0.80 = $110.40, which takes 20% of the larger number.
Increases can exceed 100%. Going from 40 to 100 is a 150% increase (the value grew by 1.5 times its original size, to 2.5 times the original). The multiplier, 1 + p, is often the clearer way to say it: "×2.5."
Undoing an increase takes a smaller percentage. After a 25% increase, 80 becomes 100. Getting back to 80 means removing 20 from a base of 100, which is 20% -- smaller than 25% because the decrease is measured from the bigger number.
For changes that could go either direction, see the Percent Change Calculator; for drops specifically, the Percent Decrease Calculator.
Use Cases
Price Increases and Inflation
Measure how much a price, rent, or bill went up as a percentage, or apply a known increase (a 4% raise, a 7% rent hike) to see the new amount. Statistical agencies such as the BLS report consumer price changes the same way.
Markups and Pricing
Apply a percentage markup to a cost to get a selling price, or work backwards from a price that includes a percentage (a tip, a surcharge, a tax) to the amount before it was added.
Growth Metrics
Report revenue, user, or traffic growth period over period. The multiplier column makes large increases easier to communicate -- "up 300%" and "4× last year" mean the same thing, and the table shows both.
Salary Raises and Investment Gains
Work out the percentage of a raise from your old and new pay, or how much an investment gained. The 'decrease to undo' figure shows how far it could fall before you're back where you started.
Frequently Asked Questions
How do you calculate a percent increase?
Subtract the original value from the new value, divide the result by the original value, and multiply by 100. For example, going from 50 to 65 is (65 − 50) / 50 × 100 = 30% increase.
Can a percent increase be more than 100%?
Yes. Any increase larger than the original value is more than 100%. Doubling is a 100% increase, tripling is 200%, and going from 40 to 100 is 150%. There's no upper limit -- unlike a percent decrease, which can't go past 100% for values that can't drop below zero.
How do I find the original value before a percent increase?
Divide the increased value by (1 + the increase as a decimal). A bill of $138 after a 20% increase was originally $138 / 1.20 = $115. Subtracting 20% of $138 gives $110.40, which is wrong because it takes the percentage of the new value instead of the original.
Why does a 50% decrease undo a 100% increase?
Because each percentage is measured from a different starting point. A 100% increase takes 100 to 200; a 50% decrease from 200 removes 100, landing back on 100. In general, undoing an increase of p takes a decrease of p / (1 + p), which is always smaller than p.
What is the difference between percent increase and percentage points?
A percent increase is relative to the starting value; a percentage-point change is the plain difference between two percentages. An interest rate rising from 4% to 5% is a 1 percentage-point increase but a 25% increase (1 is 25% of 4).
What if the original value is zero or negative?
A percent increase from zero is undefined -- any growth from nothing is infinitely large relative to the start. For negative starting values, this calculator divides by the absolute value of the original (the convention used for percent change), so going from −20 to −5 is a 75% increase.
Methodology
The formula above is implemented as a standalone module covered by unit tests, so its worked examples are re-checked on every change to the site. It is verified against the authoritative sources listed below.
Maintained by Waqar Mushtaq. Spotted a result that looks wrong? Report it and it becomes a failing test.