Percent Change Calculator

"It went up 12%" - but by how much, exactly, and relative to what? Percent change answers the most common quantitative question in daily life: comparing a value against its earlier self. Prices, salaries, populations, grades, returns, engagement - every domain measures movement this way, and the arithmetic is exactly one formula: (new - old) / old x 100.

Percent Change Calculator applies it instantly and transparently. Enter the old value and the new value; get the percentage change with sign, the exact absolute difference, and the full formula shown step by step so the answer is never a black box. Increases and decreases are both handled, negatives are explained, and the precision is yours to set.

• Instant result: Type both values and the change appears immediately.
• Increase or decrease: The direction is explicit in the output.
• Exact difference: The absolute change alongside the percentage.
• Step-by-step formula: The calculation shown so it can be verified.
• Adjustable precision: Up to 10 decimal places.
• Negative values explained: Sign conventions stay interpretable.
• Copy or download: Results ready for reports and notes.
• Free and private: Everything runs in your browser; nothing is uploaded.

1. Enter the old value - the starting point of the comparison.
2. Enter the new value - the current or later value.
3. Choose the precision for the percentage (0-10 decimal places).
4. Read the result: the percentage change with its direction, and the exact absolute difference.
5. Verify the formula in the step-by-step breakdown.
6. Copy or download the result for your report or document.

Example 1 - Price increase. Old 100, new 125: a 25% increase, a difference of 25. The step-by-step shows (125 - 100) / 100 x 100.

Example 2 - Discount. Old 80, new 60: a 25% decrease - the discount you actually got on the original price.

Example 3 - Revenue growth. Old 12,500, new 15,000: exactly 20% growth, with the difference of 2,500 shown in full.

Example 4 - Small but real. Old 1.09, new 1.10: a 0.9174% increase. With 4 decimal places the tool reports the true tiny movement a rounded answer would hide.

Example 5 - Reversal check. Old 100, new 50 (-50%), then old 50, new 100 (+100%): the tool makes the asymmetry of the two directions obvious - the base matters.

• The exact answer: Percentage and difference, both precise.
• No black boxes: The formula is shown, not hidden.
• Any domain: Finance, business, academics, health, data.
• Honest signs: Increases, decreases and negatives stay interpretable.
• Instant and live: No button presses, no waiting.
• Free and private: Runs entirely in the browser with nothing uploaded.