Percentage Change Calculator Online Free

How to use

Keep '% change between two values' selected, or pick another question from the list.
Type the old (starting) value and the new value.
Read the % change, the difference and the multiplier.

Good to know

Percentage change = (new − old) ÷ old × 100. A positive answer is an increase, a negative one a decrease. The multiplier (new ÷ old) tells the same story: 1.25 means the new value is 125% of the old one.

Always divide by the old value. That is why 400 → 500 is +25% while 500 → 400 is −20%. Prices, sales figures, population and marks from one exam to the next are all compared this way; inflation and share returns are percentage changes too.

The other modes: add or take off a percentage (₹1,000 + 10% = ₹1,100) and find the value before a change (a price of ₹1,180 after an 18% rise was ₹1,000). If the old value is 0, a percentage change cannot be calculated; quote the difference instead.

Questions

What is the formula for percentage change?

(New value − Old value) ÷ Old value × 100. If the answer is negative, it is a decrease.

What is the percentage change from 80 to 100?

(100 − 80) ÷ 80 × 100 = 25% increase.

Is percentage change the same as percentage difference?

No. Percentage change compares to the starting value. Percentage difference compares two values with no 'before' and 'after', using their average: |a − b| ÷ ((a + b) ÷ 2) × 100.

How do I work out a change in percentage points?

Subtract the two percentages. Interest going from 8% to 9% is a rise of 1 percentage point, but a 12.5% change in the rate itself.

Can the change be more than 100%?

An increase can: 100 → 350 is +250%. A decrease cannot go below −100%, which means the value dropped to zero.

Last updated: 27 October 2026