Percentage Decrease Calculator

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% loss. Understanding the cost of not investing can help put market dips into long-term context.

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.