Percentage Change Calculator
Calculate percentage increase or decrease between values, or find new value after a % change
Mode 1
Calculate Percentage Change
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Mode 2
Find New Value after % Change
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Formulas
% Change: ((New − Old) / |Old|) × 100
New Value (increase): Original × (1 + % / 100)
New Value (decrease): Original × (1 − % / 100)
What is a Percentage Change Calculator?
Percentage change measures how much a value has increased or decreased relative to its original value. It is widely used in finance (stock returns, revenue growth), science (experimental results), and everyday comparisons (price changes, salary hikes).
This calculator also handles reverse calculations — finding the original value when you know the new value and the percentage change, making it useful for both forward and backward analysis.
lightbulb Example Calculation
Scenario: Ms. Aarti Jain, stock investor from Jaipur — bought shares at ₹800 each, now trading at ₹1,050. Also tracking her salary hike from ₹55,000 to ₹63,000/month after appraisal
1Change = New − Old = 1000 − 800 = 200
2% Change = (200 / 800) × 100 = 25%
3Positive value → 25% increase
✓ Result: +25% increase from ₹800 to ₹1,000
help_outlineHow to Use the Percentage Change Calculator
- Choose Mode 1 if you have two values and want to know the % change, or Mode 2 if you want to find the new value after applying a known % change.
- For Mode 1: Enter the original (Old) value and the final (New) value. The result shows percentage change and the absolute numeric change.
- For Mode 2: Enter the original value, the percentage amount, and select whether it is an increase or decrease from the dropdown.
- Results update live as you type — positive percentage change indicates increase, negative indicates decrease.
- The result card color changes to green for increase and red for decrease, giving instant visual feedback.
Benefits
- Instantly identify whether a value increased or decreased — no manual arithmetic needed
- Mode 2 lets you find the new value after applying any % change in seconds
- Correctly handles negative values — losses, temperature drops, and revenue declines
- Absolute change displayed alongside % for full context (e.g., ₹5,000 gain = 25% rise)
- Useful for salary hike verification, stock return checks, and price change tracking
Key Terms
- Percentage Change
- ((New − Old) / |Old|) × 100; positive means increase, negative means decrease
- Absolute Change
- The raw numeric difference (New − Old) before expressing as a percentage
- Old / Base Value
- The starting reference point — the denominator in the percentage change formula
- Percentage Increase
- When new value exceeds old; result is a positive percentage
- Percentage Decrease
- When new value is below old; result is a negative percentage (capped at −100%)
quizFrequently Asked Questions
What is the difference between percentage change and percentage difference?
Percentage change uses the OLD value as the base: ((New − Old) / Old) × 100. It has a clear starting point and ending point. Percentage difference uses the AVERAGE of both values: (|A − B| / ((A + B) / 2)) × 100 — used when neither value is more "original" than the other (e.g., comparing two cities' populations). Use percentage change for time-series comparisons.
Can percentage change exceed 100%?
Yes for increases — no limit. If a stock goes from ₹100 to ₹300, the change is +200%. For decreases, the maximum is −100% (when the value falls to zero). A value cannot decrease by more than 100% of itself. This asymmetry is why percentage gains and losses don't cancel each other out — a 50% loss followed by a 50% gain leaves you at 75% of the original.
What if the old value is zero?
Percentage change is undefined when the old value is zero because division by zero is mathematically impossible. This occurs when a product had zero previous sales or a company had zero base-year revenue. In such cases, report the absolute change (e.g., "revenue grew from ₹0 to ₹10 Lakh") rather than a percentage. Some analysts use a small non-zero base as a workaround, but it distorts the result.
How do I verify my salary hike using this calculator?
Enter your current (old) salary and new salary in Mode 1. Example: ₹55,000 → ₹63,000 gives ((63,000 − 55,000) / 55,000) × 100 = 14.5% hike. Use Mode 2 to find what your salary becomes after a promised hike — enter current salary, enter 12 (for 12%), select "Increase by %," to get ₹61,600.
How is this different from a simple percentage calculator?
A simple percentage calculator answers "What is 20% of 500?" (= 100). The percentage change calculator answers "By what % did the value change from 500 to 600?" (= 20%). Both involve percentages but address different questions. The change calculator is directional — it compares two values over time — while a simple percentage calculator applies a rate to a base.