Percentage Decrease Calculator
Enter your original and new values to instantly calculate the exact percentage decrease. Free, fast, and no signup required.
Percentage decrease is a measure of how much a value has dropped compared to its original amount, expressed as a percentage. It tells you the relative size of a reduction. For example, if a store reduces the price of a jacket from $120 to $90, the percentage decrease is 25% — meaning the price fell by one quarter of its original value.
Understanding percentage decrease is essential in many areas of daily life. Whether you are tracking how much your electricity bill went down, analyzing a decline in sales revenue, measuring weight loss progress, or comparing discounted prices while shopping, the concept of percentage decrease helps you put changes into perspective.
A percentage decrease is different from an absolute decrease. An absolute decrease simply tells you the raw number difference (e.g., "$30 less"), while a percentage decrease tells you the proportional change relative to the starting point (e.g., "25% less"). The percentage gives more context because it accounts for the scale of the original value.
For example, if you need to find the percentage decrease between two numbers, simply enter them into the calculator above. You can also use it to figure out how to decrease a number by a percentage — just enter the starting number and the target number to see the exact drop.
How to Calculate Percentage Decrease
The percentage decrease formula is straightforward. You need two numbers: the original value (the starting point) and the new value (the smaller number after the decrease).
Step-by-Step Instructions
Step 1: Find the difference. Subtract the new value from the original value. This gives you the absolute amount of decrease. For example, if your original value is 500 and the new value is 350, the difference is 500 − 350 = 150.
Step 2: Divide by the original. Take the difference and divide it by the original value. This converts the absolute change into a decimal proportion. Using our example: 150 ÷ 500 = 0.3.
Step 3: Multiply by 100. Convert the decimal to a percentage by multiplying by 100. So 0.3 × 100 = 30%. The value decreased by 30%.
Quick tip: If the new value is larger than the original, the result will be negative — this means the value actually increased, not decreased. Try our Percentage Increase Calculator instead.
How to Calculate Percentage Decrease in Excel
If you work with spreadsheets, calculating percentage decrease in Excel is simple. Put the original value in cell A1 and the new value in cell B1, then use this formula in cell C1:
Format cell C1 as a percentage (right-click → Format Cells → Percentage). This works in Google Sheets, LibreOffice Calc, and all major spreadsheet applications. For a column of values, simply drag the formula down to apply it to multiple rows.
This excel formula for percentage decrease also works as a percentage decrease formula excel function in Google Sheets. If you need to calculate both percentage increase and decrease in a spreadsheet, use the same logic — just swap the subtraction order. You can download our free percentage increase and decrease worksheet template to practice with real data.
When Do You Need a Percentage Decrease Calculator?
While the formula is simple, many people prefer using an online calculator for speed, accuracy, and convenience. Here are the most common real-world scenarios where calculating percentage decrease is useful:
Shopping & Retail
Compare original prices vs sale prices to see the real discount percentage. A $200 item on sale for $149 is a 25.5% decrease.
Business & Finance
Track revenue decline, cost reduction, budget cuts, or stock price drops in quarterly reports and financial analysis.
Health & Fitness
Measure weight loss progress, calorie reduction, or decline in cholesterol levels over time.
Education
Solve math homework problems involving percentage decrease, prepare for exams, or verify manual calculations.
Real Estate
Calculate how much property values or rental prices have dropped in a market downturn.
Data Analysis
Compare metrics across time periods — website traffic decline, conversion rate drops, or user churn rates.
Percentage Decrease Examples
Click any example below to see the full step-by-step calculation. These cover common real-world scenarios to help you understand how percentage decrease works in practice.
Detailed Worked Example
Let's say your monthly electricity bill was $180 last month and dropped to $135 this month. To find the percentage decrease:
Step 1: Difference = $180 − $135 = $45
Step 2: Divide = $45 ÷ $180 = 0.25
Step 3: Multiply = 0.25 × 100 = 25%
Your electricity bill decreased by 25%. This means you used (or were charged for) one quarter less electricity compared to the previous month.
Percentage Decrease vs. Other Percentage Calculations
It is easy to confuse percentage decrease with related concepts. Here is how they differ:
Percentage Decrease vs. Percentage Increase
Percentage decrease measures how much a value went down. Percentage increase measures how much a value went up. The formulas are similar, but the subtraction is reversed. If the new value is smaller, it is a decrease; if larger, it is an increase.
Percentage Decrease vs. Percentage Change
Percentage change is the broader term that covers both increases and decreases. A positive percentage change means growth; a negative percentage change means decline. Percentage decrease is simply the negative version of percentage change.
Percentage Decrease vs. Percentage Difference
Percentage difference compares two values without specifying which is the "original." It is used when neither value is clearly the starting point. Percentage decrease always has a clear before (original) and after (new) relationship.
Frequently Asked Questions
Related Percentage Calculators
Need a different type of percentage calculation? Try one of our other free tools: