Go beyond the basics — chain multiple changes or convert between percentage points and relative percentages.
Apply several percentage changes one after another to a starting value. Great for multi-year growth, discounts stacked on discounts, or sequential price changes.
Percentage changes to apply (use − for decrease):
When a rate changes from one percentage to another, there are two ways to measure it. A move from 4% to 6% is a 2 percentage point rise but a 50% relative increase. Enter both rates to see both.
Ready-to-use percentage change lookup tables for common scenarios.
| % Change | Multiplier | Reverse (undo) | 100 → ? | 500 → ? | 1,000 → ? | 10,000 → ? |
|---|
| Original Price | −25% | −15% | −10% | −5% | +5% | +10% | +15% | +25% |
|---|
| Start Value | 1 Year (+10%) | 2 Years | 3 Years | 5 Years | 10 Years | Total % Change |
|---|
| If new value is | After +10% | After +20% | After +50% | After −10% | After −20% | After −50% |
|---|
The standard formula for percentage change is straightforward. Subtract the original value from the new value, divide by the original value, then multiply by 100.
If the result is positive, the value went up. If negative, it went down. A result of 0 means no change at all.
For example: a product price rises from $80 to $100. The change is (100 − 80) ÷ 80 × 100 = 25% increase.
This formula works for prices, salaries, test scores, stock values, population counts, temperatures, and any other number you can name.
Percentage change always starts from a specific reference point (the old value). It has a direction — increase or decrease.
Percentage difference has no "before" or "after." It compares two values as equals using their average as the base. The formula is: |A − B| ÷ ((A + B) ÷ 2) × 100.
Use percentage change when tracking how something moved over time. Use percentage difference when comparing two separate measurements with no clear starting point.
To find the original value before a percentage change was applied, divide the current value by the multiplier (1 + percent ÷ 100).
Example: a salary is now $57,500 after a 15% raise. The original salary was 57,500 ÷ 1.15 = $50,000.
For a decrease: a product costs $68 after a 20% discount. The original price was 68 ÷ 0.80 = $85.
Our "Find Original Value" mode does this automatically — just enter the final value and the percentage change.
Dividing by the new value instead of the old value is the most common error. Always divide by the starting (original) number.
Confusing percentage points with percent change. Moving from a 5% rate to a 10% rate is a 5 percentage point increase but a 100% relative increase.
Assuming stacked changes add up. A 20% increase followed by a 20% decrease does not return to the original value — it leaves you at 96% of where you started.
Ignoring the sign. A negative percentage change is a decrease, not just a smaller increase. Always check the direction of your result.
Investors use percentage change to track how an asset's price has moved since purchase or since the last trading session. A stock that rises from $150 to $165 has gained 10%. Because percentage change is scale-free, it lets you compare a $10 stock and a $1,000 stock on equal terms.
Inflation is measured as the percentage change in a price index over a year. A 3% inflation rate means average prices rose 3% compared to the same point a year earlier. Over many years, compound growth matters a lot — 3% annual inflation turns $100 into roughly $134 over ten years.
Retailers use percentage discounts and markups constantly. A "30% off" sign means the new price is 70% of the original. Adding a 20% markup to a wholesale cost gives a retail price 1.2 times higher.
Salaries and wages are often discussed in percentage terms — a 5% annual raise, for instance. Knowing the reverse formula lets you find your pre-raise salary from your current pay and the percentage increase you received.
Scientists report percentage change when comparing experimental results. A drug that reduces a symptom from a baseline of 80 points to 52 points achieved a 35% reduction. This makes results comparable across studies that used different measurement scales or sample sizes.
In statistics, relative change (percentage change) is preferred over absolute change when the baseline values differ widely. A 1-unit increase from 2 to 3 is a 50% change; the same 1-unit increase from 100 to 101 is only 1% — a critical distinction when interpreting data.