Skip to Content

Percentage Increase Calculator

Enter any two numbers below to find the percentage increase from the first value to the second. The result appears instantly — along with the formula used and a plain-English explanation of what it means.

Percentage Increase Calculator

Result

0%
((125 - 100) ÷ 100) × 100 = 25%
Enter values above to calculate the percentage increase.

What Is Percentage Increase?

Percentage increase measures how much a value has grown, expressed as a proportion of the original value. A salary rising from $40,000 to $46,000 has increased by 15% — meaning it grew by 15 cents for every dollar it started at.

The key word is original. Percentage increase is always calculated relative to where you started, not where you ended up. Getting this direction wrong is the most common mistake people make.

The Percentage Increase Formula

There is one standard formula used everywhere — from school textbooks to financial reports:

Percentage Increase = ((New Value − Old Value) ÷ Old Value) × 100

Break it down:

  • New Value − Old Value — gives you the raw amount of increase
  • ÷ Old Value — converts that increase into a fraction of the original
  • × 100 — turns that fraction into a percentage

If the result is positive, the value went up. If it is negative, the value went down — which is technically a percentage decrease, not an increase.

Worked Example — Step by Step

A gym membership cost $45 per month last year. This year it costs $54. What is the percentage increase?

  1. Subtract the old value from the new value: $54 − $45 = $9
  2. Divide by the old value: $9 ÷ $45 = 0.2
  3. Multiply by 100: 0.2 × 100 = 20%

The gym membership increased by 20%. That means for every $1 you paid before, you are now paying an extra $0.20.

Common Percentage Increase Questions — Answered

What is a 10% increase on $250?

Multiply $250 by 0.10 to get the increase amount: $25. Add it back: $250 + $25 = $275. You can also multiply $250 by 1.10 directly to get the same answer.

What is a 25% increase on 80?

80 × 0.25 = 20. So 80 + 20 = 100. Or: 80 × 1.25 = 100.

My value went from 200 to 350. What is the percentage increase?

(350 − 200) ÷ 200 × 100 = 150 ÷ 200 × 100 = 75%.

Is percentage increase the same as percentage difference?

No. Percentage increase compares a new value to a specific original value — direction matters. Percentage difference compares two values without assigning either as the "original" — it is symmetrical and used when there is no clear before/after relationship.

Can percentage increase be more than 100%?

Yes. If a value doubles, that is a 100% increase. If it triples, that is a 200% increase. There is no upper limit — a value rising from 10 to 1,000 is a 9,900% increase.

Where Percentage Increase Is Used

Understanding percentage increase shows up constantly in everyday decisions:

  • Salary negotiations — evaluating whether a raise offer is meaningful relative to your current pay
  • Investment returns — comparing how much a stock, property, or portfolio has grown
  • Retail prices — spotting whether an advertised deal is actually a good one
  • Business metrics — tracking revenue, traffic, or customer growth from one period to the next
  • School and exams — a standard topic in GCSE, SAT, and most national math curricula

Percentage Increase vs Percentage Decrease — What Is the Difference?

The formula is identical. The only difference is the sign of the result:

  • A positive result = percentage increase (value went up)
  • A negative result = percentage decrease (value went down)

Example: a product drops from $80 to $60. (60 − 80) ÷ 80 × 100 = −25%. That is a 25% decrease, not an increase.

Quick Reference — Common Percentage Increases

Increase %Multiply byExample: 100 becomes…
5%1.05105
10%1.10110
15%1.15115
20%1.20120
25%1.25125
50%1.50150
100%2.00200

Frequently Asked Questions

How do I calculate percentage increase without a calculator?

Subtract the old value from the new value. Divide the result by the old value. Multiply by 100. For quick mental estimates, round the numbers first — the answer will be close enough for most decisions.

What if my old value is zero?

Percentage increase is undefined when the original value is zero. You cannot divide by zero. In this case, report the absolute change (the raw number it grew to) instead.

Does inflation use percentage increase?

Yes. An inflation rate of 3% means the average price level increased by 3% compared to the previous year — calculated using exactly the same formula.

How is compound growth different from percentage increase?

A single percentage increase measures growth over one period. Compound growth applies a percentage increase repeatedly, with each period's result becoming the new starting point. A 10% increase applied three times is not 30% — it is 33.1%, because each 10% is calculated on a larger number than the last.

Related Calculators