What is the formula for percentage decrease?

Percentage Decrease = ((Original Value − New Value) ÷ Original Value) × 100. For example, from 100 to 75: ((100 − 75) ÷ 100) × 100 = 25%.

Can a percentage decrease be more than 100%?

No. A percentage decrease can be at most 100%, which means the value has gone to zero. Negative values would indicate a different measure.

Is a 50% decrease the opposite of a 50% increase?

No! A 50% increase on 100 gives 150, but a 50% decrease on 150 gives 75, not 100. Percentage changes are asymmetric.

How do I calculate a salary decrease?

Use: New Salary = Original × (1 − Decrease% ÷ 100). A 10% decrease on $60,000: $60,000 × 0.90 = $54,000.

How do I stack two discounts?

Apply them one after the other. 20% off then 10% off is 100 × 0.80 × 0.90 = 72, a 28% total reduction — not 30%.

How do I find the value before a decrease?

Divide the current value by (1 − decrease% ÷ 100). If $80 is the price after 20% off, the original was $80 ÷ 0.80 = $100.

Is percentage decrease the same as percentage difference?

No. Percentage decrease compares against a known starting value; percentage difference compares two values against their average and is always positive.

Percentage Decrease Calculator

Enter two values and get the percentage decrease instantly, with the steps shown.

What is the percentage change from old to new?

Original value→New value

25%

0After 100

Before: 80; 100% baseline
Change: +20; +25% of 80
After: 100; after the increase

Before 80 is the 100% baseline. The added segment is 20, which is +25% of that baseline — the value grows.

That is an increase of 20 measured against the original value 80 — the original is always the denominator.

Absolute change: 20

Formula

Find the difference: 100 − 80 = 20

Divide by the original: 20 ÷ 80 = 0.25

Multiply by 100: 0.25 × 100 = 25%

Verify

80 + 20 = 100

Check it backwards: applying that percent to the original returns the new value.

Instant answer

How do you calculate a percentage decrease?

Going from 100 to 75 is a 25% decrease.

Percentage decrease = ((Original − New) ÷ Original) × 100. Going from 100 to 75 is a 25% decrease, because the 25-unit drop is measured against the original 100.

Formula: % Decrease = ((Original Value − New Value) ÷ Original Value) × 100
Definition: Percentage decrease is the reduction from an earlier value to a later value, expressed as a proportion of the earlier (original) value.

Find the difference:100 − 75 = 25
Divide by the original:25 ÷ 100 = 0.25
Multiply by 100:0.25 × 100 = 25%

How to use

01Enter the original value — The starting or higher value.
02Enter the new value — The current or lower value.
03See the decrease — The percentage decrease appears instantly.

Tab to move between fields · Results update instantly as you typeResults update instantly as you type

⚡ Quick Answer

Percentage decrease = ((Original − New) ÷ Original) × 100. Going from 100 to 75 is a 25% decrease, because the 25-unit drop is measured against the original 100.

How to Calculate Percentage Decrease

Percentage decrease tells you how much a value has fallen compared to where it started. It's essential for tracking price drops, weight loss progress, declining expenses, or any metric that moves downward. The formula mirrors percentage increase but focuses on the reduction.

The Formula: ((Original − New) ÷ Original) × 100

Notice that a decrease from 100 to 75 is 25%, but a decrease from 200 to 175 is only 12.5% — even though both drop by 25 units. The percentage depends on the starting point, which is why this calculator is so useful for putting changes into perspective.

When You'll Use This

Sale prices: A laptop dropped from $1,200 to $899. That's a 25.08% markdown. For quick sale-price math, try the Discount Calculator.
Weight loss: Going from 190 lbs to 172 lbs is a 9.47% decrease — a meaningful milestone.
Budget cuts: A department's annual budget was reduced from $500,000 to $425,000 — a 15% decrease that requires strategic reallocation.
Stock decline: A share price fell from $72 to $54. That's a 25% decrease, because 18 ÷ 72 = 0.25. See the same method step by step in how to calculate percentage decrease.

Common Pitfall: Asymmetry of Percentages

A 50% decrease followed by a 50% increase does not bring you back to the original value. If $100 drops 50% to $50, a 50% increase on $50 only gets you to $75. This asymmetry is a frequent source of confusion — and a good reason to use precise tools. For the opposite direction, see our Percentage Increase Calculator. Dive deeper in our article on how to calculate percentage decrease.

Common Percentage Decrease Examples

Every row below links to the calculator with the values pre-filled so you can verify or adjust to your own numbers.

Decrease	From → To	Drop	Open
5% decrease	100 → 95	−5	Calculate
10% decrease	100 → 90	−10	Calculate
15% decrease	100 → 85	−15	Calculate
20% decrease	100 → 80	−20	Calculate
25% decrease	100 → 75	−25	Calculate
30% decrease	100 → 70	−30	Calculate
40% decrease	100 → 60	−40	Calculate
50% decrease	100 → 50	−50	Calculate
60% decrease	100 → 40	−60	Calculate
75% decrease	100 → 25	−75	Calculate

The Formula Explained in Plain English

A decrease answers one question: how much of the starting value disappeared? Three steps:

Measure the drop. Original − New. From 100 to 75, the drop is 25.
Compare it with the starting point. 25 ÷ 100 = 0.25.
Convert to a percentage. 0.25 × 100 = 25%.

To apply a decrease directly, multiply by (1 − rate): a 15% reduction on 240 is 240 × 0.85 = 204. To find the value before a reduction, divide instead — that is exactly what the Reverse Percentage Calculator does.

Visualising a Percentage Decrease

Each bar shows what is left of a starting value of 100 after the reduction:

−10%

100 → 90

−25%

100 → 75

−40%

100 → 60

−50%

100 → 50

−75%

100 → 25

Solid bar = what remains. Grey bar = the amount removed.

Common Mistakes to Avoid

Dividing by the new value. The denominator is always the original figure — using the smaller number inflates the result.
Expecting decreases to reverse increases. −50% then +50% ends at 75% of the start.
Stacking discounts by adding them. 20% off then 10% off is a 28% total reduction, not 30%.
Reporting a decrease above 100%. A value can fall by at most 100% before it reaches zero; anything beyond that is a negative value, not a bigger percentage drop.
Mixing up percent and percentage points. An interest rate falling from 6% to 4% is a 2 percentage-point fall and a 33.33% decrease.

Where People Use Percentage Decrease

Use case	Typical question	Best tool
Sales and markdowns	What do I pay after 30% off?	Discount Calculator
Removing tax	What is the net price without VAT?	VAT Calculator
Budget and cost cuts	How deep is a $75,000 cut on $500,000?	Percentage Decrease
Undoing a reduction	What was the price before the sale?	Reverse Percentage
Progress tracking	What share of the target have I reached?	What Percentage

How This Calculator Works

The drop is divided by the absolute value of the original figure and multiplied by 100, then rounded to two decimals for display. Everything runs locally in your browser — no values leave your device. When the original value is 0 the tool returns "N/A" because a percentage change from zero is undefined.

Method reference: the definition follows the standard relative change convention, and the percent versus percentage-point distinction matches the reporting practice of statistical agencies such as Eurostat. Reviewed and maintained by the Snap Percent Calc editorial team.

Percentage decrease — worked examples

Percentage decrease — worked examples
Question	Calculation	Answer	Open
100 → 90	((100 − 90) ÷ 100) × 100	10%	Prefilled
200 → 150	((200 − 150) ÷ 200) × 100	25%	Prefilled
80 → 60	((80 − 60) ÷ 80) × 100	25%	Prefilled
1200 → 899	((1200 − 899) ÷ 1200) × 100	≈ 25.08%	Prefilled
72 → 54	((72 − 54) ÷ 72) × 100	25%	Prefilled
190 → 172	((190 − 172) ÷ 190) × 100	≈ 9.47%	Prefilled
500000 → 425000	((500000 − 425000) ÷ 500000) × 100	15%	Prefilled

Every figure above is produced by the same calculation engine that powers the calculator on this page.

Calculation method and limitations

Method: The drop between the two values is divided by the original value and multiplied by 100. The original value is always the denominator.

Limitations

A decrease cannot exceed 100% unless the new value is negative.
Increases and decreases are not symmetric: −50% then +50% leaves you 25% below the start.
A decrease from 0 is undefined.

Method and examples last reviewed August 6, 2026 by the Snap Percent Calc editorial team. All calculations run locally in your browser.