Percentage Decrease Calculator
Calculate the percentage decrease between any two values instantly. Enter your original and new value to see the exact percentage drop, decrease amount and step-by-step working. Free, no sign-up needed.
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How to Calculate Percentage Decrease
To calculate a percentage decrease, subtract the new value from the original value, divide the result by the original value and multiply by 100. This gives you the percentage by which the value has fallen.
Common Percentage Decrease Examples
| Situation | Decrease | Example |
|---|---|---|
| Sale discount | 20–50% | £80 item reduced to £60 = 25% off |
| Salary cut | 5–15% | £50,000 reduced to £45,000 = 10% cut |
| Stock market drop | 10–30% | Share at £5 falls to £3.50 = 30% drop |
| Weight loss | 5–10% | 90kg to 81kg = 10% reduction |
| Energy bill reduction | 5–20% | £200/month to £170/month = 15% saving |
Percentage Decrease vs Percentage Difference
These are two different calculations often confused with each other. A percentage decrease measures how much a value has fallen relative to the original — it always uses the original value as the base. A percentage difference compares two values without specifying which is the reference point — it uses the average of both values as the base.
- Use percentage decrease when comparing a new value to a known starting point (prices, weights, scores)
- Use percentage difference when comparing two values of equal standing with no clear "original"
- Always check which formula applies to your situation — using the wrong one gives a misleading result
When to Use a Percentage Decrease Calculator
- Shopping and discounts — verify the actual percentage saving on a sale item
- Finance and investing — calculate the percentage drop in a share price or portfolio value
- Weight loss tracking — measure progress as a percentage of starting weight
- Business metrics — track revenue drops, cost reductions or headcount changes
- Academic results — calculate the percentage fall between two test scores
- Energy and utility bills — measure savings after switching provider or reducing usage
FAQs
What is the formula for percentage decrease?
((Original Value − New Value) ÷ Original Value) × 100. For example, a drop from 200 to 150 gives a 25% decrease.
Can I use this for weight loss tracking?
Yes — enter your starting weight as the original value and your current weight as the new value to see your percentage loss.
What if my new value is higher than the original?
That’s a percentage increase, not a decrease. Use our Percentage Increase Calculator for that.
Is this the same as percentage difference?
No. Percentage decrease measures a drop from a specific starting point. Percentage difference compares two values without a fixed original.
Is this calculator free?
Yes completely free with no sign-up needed.