Find the percentage decrease between any two numbers instantly. Enter the original and new lower value — get the result with full step-by-step working shown.
Enter the original (higher) value and the new (lower) value to find the exact percentage decrease between them.
Enter the original value and the percentage decrease to calculate what the new (lower) value will be.
Know the new (reduced) value and the % decrease applied? Reverse-calculate the original value before the decrease.
A percentage decrease expresses by how much a value has fallen relative to its original amount. Whether you're tracking a price drop, a reduction in salary, a fall in test scores, or a decline in business revenue, the percentage decrease formula gives you a clear, standardised way to measure and communicate that reduction. Instead of saying "the price dropped by $20," you can say "the price dropped by 25%" — far more meaningful across different contexts.
Our free percentage decrease calculator handles all three calculation types instantly: finding the % decrease between two values, finding the new value after a known % decrease, and reverse-calculating the original value before a % decrease was applied.
% Decrease = ((Original Value − New Value) ÷ Original Value) × 100
Always divide by the original value — not the new (lower) value. The result is always expressed as a positive number when the new value is lower than the original. If the new value is actually higher, the formula produces a negative result, which means it is a percentage increase, not a decrease.
Question: A jacket's price dropped from $120 to $90. What is the percentage decrease?
Step 1: Difference = $120 − $90 = $30
Step 2: Divide by original: $30 ÷ $120 = 0.25
Step 3: Multiply by 100: 0.25 × 100 = 25% decrease
Question: A town's population fell from 84,000 to 63,000. What is the percentage decrease?
Step 1: Difference = 84,000 − 63,000 = 21,000
Step 2: 21,000 ÷ 84,000 = 0.25
Step 3: 0.25 × 100 = 25% decrease
If you know the original value and the percentage it will decrease by, use this formula to find the resulting new value directly:
New Value = Original Value × (1 − % Decrease ÷ 100)
New Value = $640 × (1 − 15 ÷ 100) = $640 × 0.85 = $544
Amount decreased by: $640 − $544 = $96
This is especially useful in retail, VAT, and finance situations where you have the reduced price but need the original. If a product costs $270 after a 10% decrease, what was the original price?
Original Value = New Value ÷ (1 − % Decrease ÷ 100)
Given: New price = $270, % Decrease = 10%
Original = $270 ÷ (1 − 10 ÷ 100) = $270 ÷ 0.90 = $300
Verify: $300 × 0.90 = $270 ✓
A very common error is dividing by the new value instead of the original value. For example, a price drop from $100 to $80: the correct answer is ((100 − 80) ÷ 100) × 100 = 20%. If you mistakenly divide by 80 you get 25% — which is wrong. Always use the original (starting) value as your denominator.
| Scenario | Original Value | New Value | % Decrease |
|---|---|---|---|
| Product sale price | $160 | $120 | 25% |
| Salary reduction | $60,000/yr | $54,000/yr | 10% |
| Weight loss | 90 kg | 81 kg | 10% |
| Monthly electricity bill | $180 | $153 | 15% |
| Website bounce rate | 72% | 54% | 25% |
| Stock price drop | $48.00 | $36.00 | 25% |
A percentage decrease is always expressed as a positive number — it specifically measures a downward movement. Percentage change uses the same formula but can produce a positive (increase) or negative (decrease) result. If you're unsure whether a value went up or down, use the percentage change calculator — it will label the direction automatically. Both tools use the original value as the denominator.
In everyday shopping, a percentage decrease in price and a percent off calculation are mathematically identical. A 30% price decrease is the same as 30% off. The distinction is mainly semantic — "percent off" is used in retail contexts. Use our dedicated percent off calculator if you want to instantly see the discounted price alongside the savings amount.
Quick answers to the most common percentage decrease questions
Use the formula: % Decrease = ((Original Value − New Value) ÷ Original Value) × 100. Example: price drops from $200 to $150 → ((200 − 150) ÷ 200) × 100 = 25% decrease. Use the calculator above for instant results with step-by-step working.
The formula is: % Decrease = ((Original − New) ÷ Original) × 100. Always divide by the original (higher) value, not the new value. The result will be a positive number when the new value is lower — meaning there was a genuine decrease.
Formula: New Value = Original Value × (1 − % Decrease ÷ 100). Example: decrease $800 by 30% → $800 × 0.70 = $560. Switch to the "Find New Value" tab in the calculator above to do this instantly with step-by-step working.
Formula: Original Value = New Value ÷ (1 − % Decrease ÷ 100). Example: a product costs $85 after a 15% decrease → $85 ÷ 0.85 = $100. Use the "Find Original Value" tab in the calculator above.
They are mathematically identical. A 25% decrease in price is the same as 25% off. The term "percent off" is mostly used in retail settings. Our percent off calculator also shows you the exact saving in currency terms alongside the discounted price.
No — a percentage decrease is capped at 100%. A 100% decrease means the value fell to exactly zero. You cannot decrease something by more than 100% of itself, because that would result in a negative value. However, if a value crosses zero into negative territory (e.g., profits turning to losses), a percentage change calculation is more appropriate.
No — this is a common misconception. Starting with $100: a 50% increase gives $150, then a 50% decrease on $150 gives $75 — not $100. Percentage changes are not symmetrical because the base value changes between calculations. Use our percentage calculator to check multi-step scenarios accurately.
Percentage decrease has a clear directional reference (original → new lower value) and divides by the original. Percentage difference compares two values without a defined starting point, using the average of both as the base. Use decrease for before/after comparisons; use difference for comparing two independent, equal-standing values.