How to Calculate Percentage Increase and Decrease

How to Calculate Percentage Increase

A percentage increase tells you how much a value has increased compared with its original value. It is commonly used when comparing an old price with a new price, calculating salary raises, measuring business growth, or analyzing changes over time.

The important part of this formula is that the difference is divided by the original value. The original value is your starting point.

Steps to Calculate Percentage Increase

1. Subtract the original value from the new value.
2. Divide the difference by the original value.
3. Multiply the result by 100.
4. The final number is the percentage increase.

<p>
  Suppose your salary increased from <strong>Rs. 200,000</strong> to
  <strong>Rs. 230,000</strong>.
</p>

<p>Increase = Rs. 230,000 − Rs. 200,000 = <strong>Rs. 30,000</strong></p>

<p>Percentage Increase = (30,000 ÷ 200,000) × 100</p>

<div class="pc-result">Percentage Increase = <strong>15%</strong></div>

You can also calculate this instantly using our Percentage Increase Calculator .

How to Calculate Percentage Decrease

Percentage decrease tells you how much a value has fallen compared with its original value. It is commonly used for discounts, price reductions, decreases in expenses, reduced sales, or changes in measurements.

Steps to Calculate Percentage Decrease

1. Subtract the new value from the original value.
2. Divide the difference by the original value.
3. Multiply by 100.
4. The result is the percentage decrease.

<p>
  A product originally costs <strong>Rs. 8,000</strong> and its price is
  reduced to <strong>Rs. 6,000</strong>.
</p>

<p>Decrease = Rs. 8,000 − Rs. 6,000 = <strong>Rs. 2,000</strong></p>

<p>Percentage Decrease = (2,000 ÷ 8,000) × 100</p>

<div class="pc-result red">Percentage Decrease = <strong>25%</strong></div>

For a quick calculation, use our Percentage Decrease Calculator .

Percentage Increase and Decrease Examples

Here are some common examples to make percentage changes easier to understand.

Percentage Increase vs Percentage Decrease

The formulas are very similar, but the direction of the change determines which formula you should use.

  <p>Use this when the new value is greater than the original value.</p>

  <p>
    <strong> (New − Original) ÷ Original × 100 </strong>
  </p>

  <a href="/percentage-increase-calculator">
    Calculate Percentage Increase →
  </a>
</div>

<div class="pc-card">
  <h3>📉 Percentage Decrease</h3>

  <p>Use this when the new value is smaller than the original value.</p>

  <p>
    <strong> (Original − New) ÷ Original × 100 </strong>
  </p>

  <a href="/percentage-decrease-calculator">
    Calculate Percentage Decrease →
  </a>
</div>

Where Are Percentage Increase and Decrease Used?

Percentage change is used in everyday life as well as in business, education, finance, shopping, and data analysis.

<div class="pc-card">
  <h3>🛍️ Discounts</h3>
  <p>
    Calculate how much a product price has decreased during a sale or
    promotion.
  </p>
</div>

<div class="pc-card">
  <h3>📊 Business Growth</h3>
  <p>
    Measure increases in revenue, customers, sales, traffic, or other
    business metrics.
  </p>
</div>

<div class="pc-card">
  <h3>📚 Education</h3>
  <p>Compare marks, scores, test results, and other numerical changes.</p>
</div>

For shopping calculations, you can also use our Discount Calculator to quickly find the discount amount and final price.

Common Percentage Calculation Mistakes

1. Using the new value instead of the original value

When calculating percentage increase or decrease, the original value is normally the reference point. Dividing by the new value can produce a different result.

2. Forgetting to multiply by 100

The decimal result must be multiplied by 100 to convert it into a percentage.

3. Confusing percentage change with percentage difference

Percentage increase and decrease use an original value as the reference point. [Percentage difference](/percentage-difference-calculator) uses the average of the two values as its reference. Learn more on our Percentage Difference Calculator page.

4. Assuming a 20% increase followed by a 20% decrease returns to the original value

It does not. Percentages are calculated relative to the value at the time of each change.

<p>A 20% decrease from 120 gives 96.</p>

<div class="pc-result red">Final value = 96, not 100.</div>

Can You Calculate a Percentage Change Backwards?

Yes. Sometimes you know the final value and the percentage change but need to find the original value.

This is known as a [reverse percentage calculation](/reverse-percentage-calculator) and is useful for working backwards from sale prices, increased prices, salaries, taxes, and other values.

Use our Reverse Percentage Calculator when you need to find the original value.

Calculate Percentage Increase or Decrease Online

You don't need to perform every calculation manually. Our free Percentage Calculator makes it easy to calculate percentages quickly and accurately.

Simply enter your numbers, choose the calculation you need, and get your result instantly.

<p>
  Try our free percentage calculator or choose a specialized calculator for
  percentage increase, decrease, difference, discounts, and more.
</p>

<div class="pc-button"><a href="/">Open Percentage Calculator →</a></div>

Frequently Asked Questions