Calculate percentage increase, decrease, or difference between any two numbers. Works for revenue growth, price changes, discounts, test scores, and more.
Solve for any missing variable — find what value results from a percentage change, or what percentage change connects two values.
Calculate percentage change across multiple periods or items at once. Enter a starting value and each period's value.
Percentage change expresses how much a value has grown or shrunk relative to its original size. It's one of the most universally useful calculations in business, finance, science, and daily life — yet it's easy to get wrong when working with negative numbers, zeroes, or when confusing percentage change with percentage points.
Percentage Change = ((New Value − Original Value) ÷ Original Value) × 100
If revenue grew from $80,000 to $96,000: ((96,000 − 80,000) ÷ 80,000) × 100 = (16,000 ÷ 80,000) × 100 = +20%. If a stock fell from $150 to $127.50: ((127.50 − 150) ÷ 150) × 100 = (−22.50 ÷ 150) × 100 = −15%.
| Scenario | Original | New Value | % Change | Interpretation |
|---|---|---|---|---|
| Price discount | $120 | $90 | −25% | 25% off |
| Salary raise | $65,000 | $71,500 | +10% | 10% raise |
| Revenue growth | $1.2M | $1.5M | +25% | Q-o-Q growth |
| Weight change | 195 lbs | 175 lbs | −10.3% | Lost 10.3% body weight |
| Interest rate | 3.5% | 4.25% | +21.4% | Rate rose 0.75 ppt |
| Stock drop | $250 | $180 | −28% | Bear market decline |
| Test score | 72 | 88 | +22.2% | Score improved |
| Population | 45,000 | 52,000 | +15.6% | City growth |
If you know the new value and the percentage change, you can find the original: Original = New Value ÷ (1 + % Change ÷ 100). If a product now costs $135 after a 12.5% price increase, the original price was $135 ÷ 1.125 = $120. This is critical when reverse-engineering discounts, tax-inclusive prices, or commission structures.
| % Change | What it means | Example (from $100) | Multiplier |
|---|---|---|---|
| +5% | Small increase | $100 → $105 | ×1.05 |
| +10% | Modest growth | $100 → $110 | ×1.10 |
| +25% | Strong growth | $100 → $125 | ×1.25 |
| +50% | Half again more | $100 → $150 | ×1.50 |
| +100% | Doubled | $100 → $200 | ×2.00 |
| +200% | Tripled | $100 → $300 | ×3.00 |
| −10% | Small decline | $100 → $90 | ×0.90 |
| −25% | Significant loss | $100 → $75 | ×0.75 |
| −50% | Halved | $100 → $50 | ×0.50 |
| −75% | Lost three quarters | $100 → $25 | ×0.25 |
Percentage change has a direction — it measures change from one specific starting point. Percentage difference is symmetric — it measures how different two numbers are without implying which came first. Percentage Difference = |A − B| ÷ ((A + B) ÷ 2) × 100. Use percentage difference when comparing two things at the same point in time (e.g., two competing prices). Use percentage change when comparing the same thing at two different points in time.
In retail, a product selling at $49.99 marked down to $34.99 is a 30% discount — calculated as (34.99−49.99)÷49.99×100. Retailers strategically price products so a round-number discount percentage (25%, 30%, 50%) ends in .99 on the sale price, making the math deliberately inconvenient to check in your head. In real estate, a home that sold for $340,000 in 2020 and $485,000 in 2024 appreciated 42.6% — more than double the typical long-run average of ~4% per year.
In investing, the S&P 500 needs to gain 25% to recover from a 20% decline — because a 20% loss on $100 leaves $80, and $80 needs a 25% gain to return to $100. This asymmetry (losses hurt more than equivalent gains help) is why preserving capital matters more than chasing gains. In portfolio management, avoiding a −30% year is worth more than gaining +30% the next year — the net result of those two years is actually a −9% cumulative return, not zero. Risk-adjusted return metrics like Sharpe ratio exist precisely because of this mathematical reality. A −50% loss requires a +100% gain just to break even. In payroll, a 3% raise on a $60,000 salary adds $1,800 — but after a subsequent 5% raise on the new $61,800 base, total compensation is $64,890, a combined increase of 8.15% from the original, not 8%.
Clinical trials report percentage change to communicate treatment effectiveness. A drug that reduces LDL cholesterol from 160 to 120 mg/dL achieved a 25% reduction — the same formula. Weight loss is commonly tracked as percentage of body weight: losing 15 lbs from a 200 lb starting weight is a 7.5% reduction, which provides more context than the absolute number alone since 15 lbs means very different things for a 120 lb person vs a 300 lb person. Blood pressure, blood glucose, VO2 max, and virtually every health metric uses percentage change as its primary reporting unit for treatment response.
Percentage change is a ratio — it measures relative magnitude, not absolute significance. Small absolute numbers produce dramatic-looking percentages. A company revenue that grows from $10,000 to $15,000 shows 50% growth — impressive until you realize it's a $5,000 increase. A large established company growing from $10B to $10.5B shows only 5% growth but added $500M in revenue. Always report both the percentage and the absolute change for a complete picture. Similarly, averages of percentage changes are misleading — the average of +50% and −50% is 0%, suggesting no change, but the actual result is a 25% loss as shown above.
Percentage change is the backbone of financial analysis. Year-over-year (YoY) revenue growth, quarter-over-quarter (QoQ) margin changes, month-over-month (MoM) user growth — all are percentage changes. Understanding how to calculate and interpret these correctly separates clear thinkers from those who get fooled by absolute numbers.
A critical mistake: adding percentage changes together. If revenue grew 20% in Year 1 and 15% in Year 2, the total growth is not 35%. Starting from $100: Year 1 → $120. Year 2 → $120 × 1.15 = $138. Actual total growth: 38%, not 35%. To compound: multiply (1 + r1) × (1 + r2) × … − 1. This matters enormously over long periods — a 7% annual return over 30 years is not 210% total growth, it's (1.07^30 − 1) = 661%.
Percentage change becomes misleading when the original value is negative. If a company's losses went from −$1M to −$500K, that's an improvement — but the formula gives ((−500K − (−1M)) ÷ (−1M)) × 100 = −50%, suggesting a decline. Most financial analysts report "N/M" (not meaningful) or "N/A" when the base period is negative. This calculator handles negative values mathematically but flags them.
Business analysts use percentage change constantly for KPI dashboards, investor reports, and performance reviews. The most common mistake is failing to specify the comparison period clearly. "Revenue up 18%" is meaningless without knowing: vs. last quarter? vs. same quarter last year? vs. the original forecast? Year-over-year (YoY) is the gold standard for seasonal businesses because it eliminates seasonality. Quarter-over-quarter (QoQ) is better for fast-moving tech companies where last quarter is the relevant baseline. Month-over-month (MoM) is most useful for early-stage growth tracking where weekly changes matter.
When presenting percentage changes to non-technical audiences, always include both the percentage and the absolute number. "Revenue grew 150%" sounds extraordinary — but if it went from $20,000 to $50,000, context changes the story entirely. Conversely, "Revenue grew $50 million" sounds huge until you know it started at $2 billion (a 2.5% increase). Strong communicators lead with whichever number supports their narrative and immediately follow with the other for credibility.
The five most frequent percentage change errors: (1) Using the wrong base — always divide by the original, not the new value. (2) Adding percentage changes instead of compounding them. (3) Confusing percentage change with percentage points when the underlying value is itself a percentage. (4) Reporting percentage change from a negative base as if it means something directionally obvious. (5) Forgetting that a 100% increase followed by a 50% decrease does not return to the original — it leaves you at 75% of where you started (100 → 200 → 100? No: 200 × 0.50 = 100 — actually this one does work out. But 50% up then 50% down: 100 → 150 → 75. Net: −25%).