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Percentage Difference

Percentage Change Calculator

Calculate the percentage increase, decrease, or rate of growth between an old starting value and a new value instantly. Includes step-by-step math, Excel shortcuts, and visual examples.

Enter Starting & Ending Values

Find the percentage increase, decrease, or growth rate from an old starting value to a new value.

Percentage Change
—%
Raw Difference (Change)—
Multiplier—
Calculation:Enter starting and ending values above to calculate
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Complete Guide to Percentage Change

Everything you need to know: the exact formula, easy 3-step calculation instructions, spreadsheet shortcuts for Excel and Google Sheets, worked examples, and when to use percentage change vs. percentage difference.

1. Fundamentals

What Is Percentage Change?

Percentage change tells you how much a number grew or shrank compared to where it started. Whenever you want to track a before-and-after change over time—such as a salary raise, a rent hike, stock market swings, or your website traffic this month—percentage change gives you the exact rate of that shift.

Everyday Examples of Percentage Change

We run into percentage change every single day. Here are a few familiar situations:

💼 Salary RaisesIf your pay goes from $50,000 to $55,000, your salary increased by +10.00%.
🏷️ Shopping DiscountsA jacket marked down from $100 to $70 represents a −30.00% price cut.
📈 Website TrafficMonthly visitors jumping from 8,000 to 12,000 represents a +50.00% surge in traffic.
🏠 Rent AdjustmentsRent rising from $1,600 to $1,680 means your monthly housing expense increased by +5.00%.

The 3 Core Rules of Percentage Change

Keep these three simple principles in mind whenever you calculate percentage change:

1

Order Matters

Going from $40 to $60 is a +50.00% increase, but dropping from $60 to $40 is a −33.33% decrease. The starting number sets the scale.

40 → 60 ≠ 60 → 40
2

Positive vs. Negative Sign

A plus sign (+) always means growth or an increase. A minus sign (−) always means a loss, drop, or discount.

(+) = Growth | (−) = Drop
3

Needs a Starting Point

You must always divide by the original starting number. Without an initial baseline, you cannot measure how much progress was made.

Divide strictly by Old Value
2. The Formula

The Percentage Change Formula

In plain words: Subtract the old number from the new number, divide by the old number, and multiply by 100.

Core Mathematical Formula
Percentage Change =(
New Value − Old Value ÷ |Old Value|
)× 100

The numerator New Value − Old Value is the raw dollar or unit change. The denominator |Old Value| is your original starting baseline.

JavaScript / Code snippet:((newValue - oldValue) / Math.abs(oldValue)) * 100
Old

Old Value (Starting Point)

Where you began before the change occurred. This could be last year's sales, your starting weight, or yesterday's stock price.

New

New Value (Ending Point)

Where you ended up. If New is greater than Old, you experienced growth (+); if New is less than Old, you experienced a drop (−).

Δ

Raw Difference (Change)

New − Old. Keeps its positive or negative sign to preserve the direction of growth or decline.

×100

Turn Into a Percent

Multiplying the decimal ratio by 100 converts it into a standard percentage (%).

💡
How negative starting numbers work:

If you start with a negative number—like going from −$50 in credit card debt to −$25 in debt—our calculator uses the absolute value |Old Value| in the denominator.

((−25 − (−50)) ÷ |−50|) × 100 = (25 ÷ 50) × 100 = +50.00%

This ensures the direction makes real-world sense: cutting your debt in half is a +50% financial improvement, not a negative decline.

3. Step-by-Step Instructions

How to Calculate Percentage Change in 3 Easy Steps

Calculating percentage change by hand or on a standard calculator takes just three quick steps:

1Step One

Find the Raw Change

Subtract your starting number from your new number. Keep the sign: a positive number means growth; a negative number means a drop.

Change = New − Old
2Step Two

Divide by Starting Value

Divide the change from Step 1 by the absolute value of your original starting number (|Old|) to find the decimal ratio.

Ratio = Change ÷ |Old|
3Step Three

Multiply by 100

Multiply the decimal ratio by 100 and attach a percent sign (%). That gives you your final percentage change!

Percentage = Ratio × 100%
Spreadsheet Guide

How to Calculate Percentage Change in Excel & Google Sheets

Need to compare sales figures, quarterly profits, or marketing benchmarks in Microsoft Excel or Google Sheets? Use these formulas to calculate percentage change automatically across your columns.

Standard (Positive Starting Value)

Standard Spreadsheet Formula

Ideal for revenues, prices, website sessions, and everyday numbers where Old Value is in cell A2 and New Value is in cell B2.

=(B2-A2)/A2

Tip: After pasting, click the Percent Style (%) button on your toolbar to format the decimal as a percentage.

Universal (Negative-Safe)

Negative Starting Value Formula

Essential when starting values can be negative (e.g. corporate net losses, sub-zero temperatures, or negative margins).

=(B2-A2)/ABS(A2)

How it works: ABS(A2) ensures the denominator is positive so an improved deficit shows as a positive growth rate.

3 Easy Steps to Use in Your Spreadsheet:

  1. Enter your Starting Value (Old) in cell A2 and your Ending Value (New) in cell B2.
  2. Paste =(B2-A2)/A2 into cell C2 and press Enter.
  3. Select cell C2 and click the Percent Style (%) button on the toolbar. Then drag the small bottom-right square down to apply the formula across all your rows!
5. Worked Examples

Worked Examples & Interactive Table

Here is how the percentage change formula works across price jumps, markdowns, negative debts, and decimals. Click Load on any row to test it in the interactive tool above.

Ex

Detailed Walkthrough: Price Rising from $40 to $60

Suppose an item originally cost $40 and the price increases to $60:

Step 1: Difference60 − 40 = +20
Step 2: Divide by Old20 ÷ 40 = 0.50
Step 3: Multiply by 1000.50 × 100 = +50.00%
Multiplier60 ÷ 40 = 1.50x
Reference examples of percentage change calculations
Old ValueNew ValueRaw ChangeMultiplierPercentage ChangeScenarioTry It
4060+20.001.50x+50.00%Price increase from $40 to $60 (+50.00% gain)
6040−20.000.67x−33.33%Price markdown from $60 to $40 (−33.33% drop)
50125+75.002.50x+150.00%Traffic jumping from 50 to 125 (more than doubled)
1001000.001.00x0.00%Identical numbers with zero change (0.00%)
-50-25+25.00—+50.00%Debt cut from −$50 to −$25 (+50.00% recovery)
12.515.75+3.251.26x+26.00%Decimal measurement increase (+26.00%)
Directional Math: In percentage change, order is fundamental. Increasing from 40 to 60 is a +50.00% rise because you divide 20 by 40. But dropping from 60 to 40 is a −33.33% decrease because you divide −20 by 60.
6. Comparison & Core Differences

Percentage Change vs. Percentage Difference

Quick Rule of Thumb: Use Percentage Change (this calculator) when tracking a before-and-after change over time. Use Percentage Difference when comparing two side-by-side items (like two store prices) where neither came first.
Before & After (Over Time)

Percentage Change

Measures how a specific value moves up or down from an old starting baseline to a new ending figure.

Formula((New Value − Old Value) ÷ |Old Value|) × 100
  • →Directional: An increase is positive (+); a decrease is negative (−).
  • →Denominator: Divided strictly by the old starting baseline.
  • →Order matters: 40 to 60 (+50%) is not the same as 60 to 40 (−33.33%).
Everyday Example: A stock rising from $40 last month to $60 today is a +50.00% gain.
Side-by-Side (No Starting Point)

Percentage Difference

Compares two equal values at the same time where neither number is the "original" or "starting" value.

Formula|A − B| ÷ ((|A| + |B|) ÷ 2) × 100
  • ✓Order doesn't matter: 40 vs 60 gives the exact same result as 60 vs 40.
  • ✓Denominator: Divided by the average of both numbers.
  • ✓Sign: Always positive (0% or greater).
Everyday Example: A $40 item at Store A vs. a $60 item at Store B gives a 40.00% difference.
Calculate Difference →

Side-by-Side Comparison: Values of 40 and 60

See how the math changes depending on whether you're evaluating a price change over time or comparing two competitors side-by-side:

Change: 40 → 60+50.00%Starting from 40 and growing to 60
Change: 60 → 40−33.33%Starting from 60 and dropping to 40
Difference: 40 vs 6040.00%Comparing Store A (40) vs Store B (60)
7. Frequently Asked Questions

Frequently Asked Questions

Straightforward answers about calculating percentage change, why order matters, and spreadsheet tricks.

How do you calculate percentage change between two numbers?
You calculate percentage change by subtracting the old number from the new number, dividing the difference by the absolute value of the old number, and multiplying by 100. For example, to find the percentage change from 40 to 60: subtract 40 from 60 to get 20, divide 20 by 40 to get 0.50, and multiply by 100 to get a +50.00% increase.
Why is the percentage from 40 to 60 (+50%) different from 60 to 40 (−33.33%)?
The percentages are different because percentage change always divides by your starting number, and the two scenarios start from completely different numbers. When going from 40 to 60, you divide the 20-point increase by 40, which equals +50.00%. When dropping from 60 to 40, you divide the 20-point decrease by 60, which equals −33.33%.
Can percentage change be greater than 100%?
Yes, percentage change can easily be greater than 100% whenever a number more than doubles its original value. For example, if website visitors jump from 50 to 125, the increase is +150.00% because the raw growth of 75 is one and a half times larger than the starting 50. There is no upper limit to percentage increase.
What does a negative percentage change mean?
A negative percentage change means that the new value decreased or dropped below the original starting value. For example, a percentage change of −25.00% indicates that the item lost a quarter of its value, such as a $100 coat discounted to $75. A percentage decrease cannot drop below −100% unless you transition into negative numbers.
How do you calculate percentage change when the starting number is negative?
When the starting number is negative, you divide the change by the absolute value of the starting number: ((New − Old) ÷ |Old|) × 100. Using the absolute value ensures that positive progress—such as paying down debt from −$50 to −$25—correctly results in a +50.00% improvement rather than a confusing negative sign.
Why can't you calculate percentage change from zero?
You cannot calculate percentage change from zero because division by zero is mathematically undefined. In the formula ((New − 0) ÷ 0) × 100, having 0 in the denominator has no mathematical meaning because no percentage of zero can ever equal a non-zero number. If you need to compare zero to another value, use our Percentage Difference Calculator instead.
How do I calculate percentage change in Excel?
To calculate percentage change in Excel or Google Sheets, use the formula =(B2-A2)/A2, where A2 holds the old starting value and B2 holds the new value. After pressing Enter, format cell C2 as a percentage using the % button on the toolbar. If your starting values might be negative, use =(B2-A2)/ABS(A2) instead.
When should I use percentage change instead of percentage difference?
Use percentage change when you have a clear starting point and ending point over time, and use percentage difference when you are comparing two separate items side-by-side with no starting value. For instance, use percentage change to measure annual salary raises or monthly revenue growth, but use percentage difference to compare prices between two different grocery stores.