Percentage Increase Calculator

Common questions

How do I calculate a percentage increase?

Subtract the old value from the new one, divide by the magnitude of the old value, then multiply by 100. From 80 to 100 that is (100 − 80) ÷ 80 × 100 = 25%. This page prints the same line under the answer for whichever pair you enter, with the divisor inside absolute-value bars as ÷ |80| × 100, so the arithmetic can be checked on paper or pasted into a document rather than taken on trust. Both the rounded headline and the computed result are shown, and Copy result copies the computed value.

How do I work out a percentage decrease here?

The same two boxes do it. Put the earlier figure in From and the later one in To even when the later one is smaller: 100 to 80 comes back as -20%, and the page writes it out as a decrease of 20% as well as showing the minus sign. There is no separate decrease mode to hunt for, because it is the same division with a negative result.

Does a 25% decrease undo a 25% increase?

No, and this is the mistake the page is built to make visible. 80 to 100 is a 25% increase, but 100 back to 80 is a 20% decrease, because the second division is by 100 rather than by 80. A percentage change is always a share of where it started, so the two directions are not mirror images. Enter both pairs and the working line shows the two different divisors.

Why will it not calculate an increase from zero?

Because it is undefined. The formula divides by the starting value, which is why a spreadsheet returns a divide-by-zero error on the same sum. The page says that instead of printing a number, and points at the percentage difference question, which divides by the average of the two values and can therefore express the gap between 0 and something.

What if the starting value is negative?

The division uses the size of the starting value rather than its sign, so going from -50 to -25 is an increase of 50%. The working line prints the absolute-value bars around the divisor, |-50| in that example, so you can see exactly which figure the result was measured against.

Can I type a comma or a percent sign into the boxes?

Yes. A grouped value such as 1,234.5 reads as 1234.5; a trailing percent sign is stripped, so 12% reads as 12. Signed decimals and scientific notation such as 1e3 are accepted. Invalid grouping or values outside the browser’s representable number range show an input message instead of a computed result.

Can I compare salary, rent, sales, costs or a supplied body weight?

Yes, as a comparison of two numbers in the same units and period basis. A salary of 40,000 rising to 42,000 is a 5% increase; 80 kg falling to 70 kg is a -12.5% change. This does not calculate take-home pay, legal rent limits, investment advice, body-fat change or a weight-loss target.

Does this give yearly growth or a compound annual growth rate?

Two endpoints give the total percentage change across the interval. Matching one-year endpoints gives that year’s YoY change, and matching one-month endpoints gives MoM change. For known values of 100 and 133.1 separated by three years, total change is 33.1%; the CAGR page under ROI Calculator uses those endpoints and three elapsed years to give a 10% annual compound equivalent. If you already have the individual annual or monthly percentage changes, Average Growth Rate under Average Calculator compares their arithmetic and compound means. APY Calculator applies a supplied rate to a known starting amount; it does not solve the rate from these endpoints.

How do I find a savings or discount percentage from two prices?

Use the original price in From and the reduced price in To. From 250 to 200 is -20%, meaning a 20% decrease or saving relative to the original price; the amount saved is 250 − 200 = 50. If you already know the discount rate, % off a price gives the final price and saving directly.

What is the percentage change formula in Excel?

For the old value in A2 and new value in B2, use =(B2-A2)/ABS(A2) and format the cell as Percentage. A zero old value makes the relative change undefined; IF(A2=0,NA(),(B2-A2)/ABS(A2)) keeps that case explicit. These are formula instructions, not a downloadable spreadsheet.

How do I calculate month-over-month or year-over-year growth?

Put the earlier period’s amount in From and the corresponding later period’s amount in To, using the same unit and period basis. Revenue of 80,000 last year and 100,000 this year gives 25% YoY growth. Matching one month with the preceding month uses the same formula for MoM growth; matching a month with the same month last year instead gives that month’s YoY change. The calculator compares the two values you supply and does not infer seasonal adjustments or dates.

How do I calculate YoY growth across three or more years?

Calculate each year against its own previous year. A supplied series of 100, 110, 99 and 118.8 has three annual changes: 10%, -10% and 20%. Use the two boxes for one pair at a time; this page does not generate a multirow history or PDF. The endpoints alone give a total 18.8% increase over three intervals. CAGR under ROI Calculator solves the compound annual equivalent from 100, 118.8 and three years, while Average Growth Rate accepts the three observed percentages to compare their arithmetic mean with the compound mean.

How do I calculate YoY growth in Excel for multiple years?

With consecutive annual amounts in B2:B5, enter =(B3-B2)/ABS(B2), format as Percentage and copy the formula down. Each row compares its own earlier year. For one compound annual equivalent across the three elapsed intervals, use =(B5/B2)^(1/3)-1 only when the starting amount is positive and the ending amount is nonnegative. These are manual formulas; no Excel workbook or PDF is produced here.

Is percentage variance the same as statistical variance?

In a comparison against a known baseline, percentage variance commonly means (actual - baseline) / |baseline| × 100. Put the baseline in From and actual in To. From 100 to 110 gives 10%. Statistical variance instead averages squared deviations from a mean; Variance under Average Calculator serves that raw-data question. This percentage comparison does not calculate portfolio covariance or project earned-value metrics.