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Percentage Change Calculator

Math

Calculate percentage increase or decrease between two values instantly. Find percentage change and absolute difference for any two numbers free.

Reviewed by the thecalcu.com team · Last updated July 9, 2026

1,000
1,250
▲ Increase
+0.00%
Absolute Change
+0
New as % of Original
0.00%

What is a % Change?

A Percentage Change Calculator measures how much a value has moved relative to its starting point, expressed as a percentage. Enter an original value and a new value, and it returns the percentage change, the absolute change, and the new value expressed as a percentage of the original, three numbers that together give a full picture of the shift.

Percentage change shows up everywhere: investment returns (a stock that rose from $45 to $54 is up 20%), business metrics (revenue up 34% year-over-year), inflation figures (CPI up 3.2%), grades (a score that improved from 68% to 79%), and sports stats. What makes it useful is that it normalizes the comparison, a $10,000 gain on a $50,000 investment (+20%) is directly comparable to a 20% gain anywhere else, regardless of units or scale.

The formula is: Percentage Change = ((New − Original) ÷ Original) × 100. A positive result is an increase, negative is a decrease, the sign alone carries the direction, so one formula covers both cases instead of the separate "increase" and "decrease" formulas some textbooks still teach.

The third output, New as % of Original, is the full ratio expressed as a percentage: (New ÷ Original) × 100. At 125%, the new value sits a quarter above the original; at 75%, it's a quarter below. That relates back to percentage change as New as % of Original = 100 + Percentage Change, a framing that's especially handy in budget or performance tracking where you care about the ratio to a baseline more than the raw delta.

For multi-year compound growth, the Percentage Calculator and a dedicated CAGR tool handle the time dimension this calculator intentionally leaves out.

Formula & Methodology

Percentage Change:
Percentage Change = ((New Value − Original Value) ÷ Original Value) × 100

Absolute Change:
Absolute Change = New Value − Original Value

New Value as % of Original:
New as % of Original = (New Value ÷ Original Value) × 100

Relationship between the three:
New as % of Original = 100 + Percentage Change

Variables:
- Original Value (O) = starting or reference value (cannot be 0)
- New Value (N) = changed or current value

Worked example, salary raise from $52,000 to $59,800:

Percentage Change = ((59,800 − 52,000) ÷ 52,000) × 100 = (7,800 ÷ 52,000) × 100 = +15%
Absolute Change = 59,800 − 52,000 = +$7,800
New as % of Original = (59,800 ÷ 52,000) × 100 = 115%

Worked example, stock price fall from $280 to $196:

Percentage Change = ((196 − 280) ÷ 280) × 100 = (−84 ÷ 280) × 100 = −30%
Absolute Change = 196 − 280 = −$84
New as % of Original = (196 ÷ 280) × 100 = 70%

Assumptions and limitations:
- If Original Value = 0, percentage change is mathematically undefined (division by zero). The calculator returns 0 for this edge case.
- Negative original values are valid but need careful interpretation, a change from −$100 to −$50 shows as a +50% "improvement" under this formula even though both numbers represent a loss.
- This calculator computes simple percentage change, not compound annual growth rate. For multi-period annualized growth, use a dedicated CAGR formula instead.

How to use this % Change calculator

  1. Enter the Original Value, the starting point or benchmark. This is the denominator in the formula. For year-over-year comparisons, use last year's figure; for tracking an investment, use the purchase price.

  2. Enter the New Value, the current or final figure. You don't need to know in advance whether it's higher or lower, the calculator handles both and shows a negative result for decreases automatically.

  3. Read the Percentage Change, the headline output. Positive means growth, negative means decline, and the size of the number tells you how large the move is relative to where you started.

  4. Check the Absolute Change, if the percentage surprises you, the absolute change grounds it in real units, whether that's dollars, points, or units sold.

  5. Use New as % of Original for ratio framing, particularly handy against a budget or target: current spend at 108% of forecast means you're 8% over.

Common Mistakes to Avoid

Swapping the base value. The original value always goes in the denominator. Accidentally dividing by the new value instead flips the sign and skews the magnitude, especially on large moves.

Confusing percentage change with percentage points. "Rates fell 2%" and "rates fell 2 percentage points" describe very different sizes of change when the starting rate is small. Keep the vocabulary straight, especially when writing up results for someone else.

Assuming symmetry between an increase and its reversal. A 50% increase followed by a 50% decrease does not return you to the original value, it lands you 25% below it, because the second percentage applies to a larger base. This trips people up constantly in investment return sequences.

Reporting percentage change without the time frame. A 20% change over one month and a 20% change over five years mean very different things. Always pair the percentage with the period it covers, or switch to CAGR if you need an annualized comparison.

Who Should Use This Calculator?

Investors tracking portfolio performance, a stock moved from $320 to $412, a fund's NAV moved from $87.50 to $104.20, this calculator answers "how much is that in percentage" in one step, plus the ratio for direct cost-basis comparison.

Students working through ratio and percent problems, percentage increase and decrease are core middle and high school math topics, and the step-by-step math here mirrors the format expected on homework and standardized tests.

Business analysts and finance teams, monthly and quarterly reviews run on MoM and YoY comparisons for revenue, costs, and headcount. This calculator handles any two numbers and shows the absolute change and ratio alongside the percentage for full context.

Journalists and anyone translating raw numbers into copy, distinguishing percentage change from percentage point change matters for accuracy, and having both values visible side by side avoids the mix-up.

Quick Reference

Scenario Original New % Change
Salary raise $52,000 $59,800 +15%
Stock drop $280 $196 −30%
Startup revenue growth $500,000 $1,500,000 +200%

For related math tools, try the Percentage Calculator for straightforward percent-of calculations, the Ratio Calculator for simplifying and comparing ratios, or the Fraction Calculator when your inputs start as fractions rather than decimals.

Frequently Asked Questions

Percentage change measures how much a value has increased or decreased relative to its original value, expressed as a percentage: Percentage Change = ((New Value − Original Value) ÷ Original Value) × 100. A positive result is an increase; a negative result is a decrease. If a stock rose from $45 to $54, the percentage change is ((54 − 45) ÷ 45) × 100 = +20%. The original value always sits in the denominator, no matter which direction the change runs.
Percentage change is relative, it compares the change to the original value. A percentage point change is a plain subtraction between two percentages. If unemployment falls from 7.5% to 6.0%, that's a −1.5 percentage point change, but the percentage change is ((6.0 − 7.5) ÷ 7.5) × 100 = −20%. Headlines blur this constantly: 'rates cut by 25%' and 'rates cut by 25 basis points' describe very different magnitudes.
Absolute change is just New Value minus Original Value, a number in the same units as your inputs, whether that's dollars, pounds, or test scores. Percentage change expresses that same gap as a share of the original, which lets you compare across wildly different scales. A $5,000 raise and a $5,000 gain on a $1,000,000 portfolio are the same absolute change but +20% versus +0.5% in relative terms.
Percentage Increase = ((New Value − Original Value) ÷ Original Value) × 100, used when New Value is larger. A CD that matures at $10,800 against a $10,000 deposit shows a percentage increase of ((10,800 − 10,000) ÷ 10,000) × 100 = 8%. That's the total increase over the whole period, for an annualized rate over multiple years, you'd need CAGR instead: (End ÷ Start)^(1/Years) − 1.
Percentage Decrease = ((Original Value − New Value) ÷ Original Value) × 100, when the original value is larger. The math is identical to percentage increase, only the interpretation flips. A stock falling from $380 to $285 shows a decrease of ((380 − 285) ÷ 380) × 100 = 25%. On this calculator, a decrease simply shows up as a negative percentage change, so you never need to pick a separate formula.
Yes, any time the new value more than doubles the original. A startup's revenue growing from $500,000 to $1,500,000 is a ((1,500,000 − 500,000) ÷ 500,000) × 100 = +200% change, the value tripled. Going from $100,000 to $1,000,000 is a +900% change (10x). There's no mathematical ceiling on increases. Decreases, on the other hand, bottom out at −100% (the value hitting zero).
It's the standard way to express returns, index moves, and economic growth. An S&P 500 move from 4,500 to 4,725 is a +5% change. Annualized fund returns are usually a compound version of percentage change, quoted as CAGR or XIRR. GDP growth and CPI inflation are both reported as year-over-year percentage change. Fund factsheet returns over 1, 3, and 5 years are compound percentage changes, not simple sums of yearly numbers.
'New as % of Original' = (New Value ÷ Original Value) × 100. A rise from $1,000 to $1,250 makes the new value 125% of the original, the same move shows as +25% in percentage change. The relationship is New as % of Original = 100 + Percentage Change. This framing is handy in budget tracking ('spend is running at 112% of last year') where you want the ratio, not just the delta.
Percentage change measures the total move between two points with no regard for time elapsed. CAGR (Compound Annual Growth Rate) smooths that same move into an equivalent annual rate: CAGR = (End Value ÷ Start Value)^(1/n) − 1, where n is years. A $10,000 investment growing to $25,900 over 10 years is a 159% total percentage change but only about 10% CAGR. Reach for a CAGR tool whenever the time dimension actually matters to your comparison.
US middle and high school math (typically grades 6–8, revisited in Algebra I) covers percentage change under ratios and proportional relationships, often alongside markup, discount, and simple interest problems. Common question types include finding the percent increase or decrease given two values, working backward to find an original price from a sale price and discount percentage, and chaining successive percentage changes. This calculator's step-by-step math mirrors the format most textbooks expect.
A basis point (bps) is one-hundredth of a percentage point, 0.01%. Finance uses it to describe small moves in interest rates and bond yields where a full percentage point is too blunt an instrument. A 25 bps Fed rate cut equals a 0.25 percentage point cut. If the federal funds rate goes from 5.50% to 5.25%, that's stated as '25 basis points,' not '0.25% lower,' to avoid the ambiguity between percentage points and percentage change.
Because it sits in the denominator of the formula, dividing by an original value of zero is mathematically undefined, there's no meaningful percentage change from nothing to something. This calculator returns 0 for that edge case rather than an error, but treat any 'from zero' scenario as a case where percentage change isn't the right metric; report the absolute change instead.
Also known as
percent change calculatorpercentage increase decreasepercentage difference calculator