Percentage Decrease Calculator

How percentage decrease is calculated

A percentage decrease measures how much smaller a number has become relative to where it began. It is how reductions in price, weight, spending and website traffic are normally described.

The formula

Subtract the new value from the old value, divide by the old value and multiply by 100. In short: percentage decrease = (old - new) / old x 100. A price that falls from 120 to 90 has dropped by 30, and 30 divided by 120 is 0.25, so the decrease is 25%.

As with any percentage change, the original value is the base. Dividing by the lower, newer figure overstates the drop.

Using the calculator

1. 1Choose "Between two values" and enter the starting value and the new, lower value.
2. 2Read the percentage decrease and the absolute difference in the result panel.
3. 3Choose "Decrease a value" to take a percentage off a number, for example 15% off 250.
4. 4If the second number is actually higher, the result switches to an increase so it stays correct.

Worked examples

Common uses

• Prices and sales: checking how deep a discount really is compared with the previous price.
• Budgets: measuring how far monthly spending has dropped after a change.
• Health and fitness: expressing weight or measurement change relative to the starting point.
• Business metrics: tracking falls in traffic, conversions or churn between two periods.

Related calculators

Use the Percentage Increase Calculator when a figure has gone up, the Discount Calculator to price a sale item, or the general Percentage Calculator for everyday percentage questions.