Percent Change Calculator
Enter an old value and a new value to calculate the percent change, absolute change, and direction. Track revenue growth, cost changes, KPI trends, and year-over-year performance.
Enter an old value and a new value to calculate the percent change, absolute change, and direction. Used for tracking revenue growth, cost changes, KPI trends, and year-over-year comparisons.
The starting or baseline value
The current or ending value
Formula
Percent Change = ((New − Old) ÷ Old) × 100 | Absolute Change = New − Old | Direction = Positive (increase) or Negative (decrease)
Percent change measures the relative growth or decline from one value to another, expressed as a percentage. Absolute change shows the raw difference. Use percent change to compare changes across different scales or time periods, such as revenue growth from $1M to $1.2M versus $100K to $120K (both 20% growth). Absolute change is useful for tracking actual dollar or unit movements.
Worked Example
Revenue increased from $1,000,000 last year to $1,200,000 this year:
Absolute change = $1,200,000 − $1,000,000 = $200,000
Percent change = ($200,000 ÷ $1,000,000) × 100 = 20%
Direction: Increase
Example with a decline — costs decreased from $50,000 to $45,000:
Absolute change = $45,000 − $50,000 = −$5,000
Percent change = (−$5,000 ÷ $50,000) × 100 = −10%
Direction: Decrease
Both 20% growth and -10% decline show the relative change. Use percent change to compare performance across different scales (e.g., comparing a $1M revenue increase to a $50K cost decrease).
Common Mistakes
1. Dividing by the new value instead of the old value
Wrong: ($200,000 ÷ $1,200,000) × 100 = 16.67%
Correct: ($200,000 ÷ $1,000,000) × 100 = 20%
The old value is the baseline; always divide by it.
2. Forgetting to handle zero or negative starting values
If old value is zero, percent change is undefined (cannot divide by zero).
If old value is negative (e.g., a loss turning into profit), the interpretation changes — use absolute value for the denominator or reconsider the baseline.
3. Confusing percent change with percentage points
If market share goes from 10% to 15%, that is a +5 percentage point increase, but a +50% percent change (5 ÷ 10 × 100).
4. Not considering the impact of reversing values
Going from $100 to $200 is a +100% increase. Going from $200 back to $100 is a −50% decrease, not −100%. This asymmetry is important for understanding losses and recoveries.
Frequently Asked Questions
Use this in your workflow
After calculating percent change, use the Margin Calculator to understand the impact on profitability. Use the ROI Calculator to evaluate investment performance. Browse all Business Calculator Hub tools.
When to use this calculator
- →Tracking year-over-year revenue, cost, or KPI growth for performance reviews and board reporting
- →Analyzing month-over-month or quarter-over-quarter changes in business metrics
- →Monitoring customer acquisition costs, retention rates, or other operational KPIs for trends
- →Comparing changes across different scales or business units with relative growth percentages
- →Assessing the impact of pricing changes, promotions, or operational improvements on results