Education
Percentage Increase Calculator – Percent Change
Last updated: June 19, 2026
A percentage increase calculator computes the relative change between an initial value and a final value, expressing the difference as a percentage. It determines the rate of growth by dividing the absolute increase by the starting value and multiplying by one hundred. The calculator also handles percentage decreases, providing absolute differences, ratio multipliers, and step-by-step arithmetic. Business analysts, retail managers, and investors use this tool to track financial growth, analyze sales trends, and calculate price adjustments over time.
Enter the original and new values. This percent increase calculator computes the percentage change, the absolute change, and the multiplier.
Quick Answer
Calculate the percentage change between two numbers. Enter the starting value and final value to find the increase or decrease percentage.
The starting number — the “before” value. · e.g. 80
The ending number — the “after” value. · e.g. 100
Formula
((new − old) / |old|) × 100
Negative results mean a decrease. We divide by the absolute value of old so the sign of the change still reads naturally when the original is negative.
Percentage increase
+25%
80 → 100 (+20)
Examples
80 → 100
+25% increase · ×1.25
100 → 80
−20% decrease · ×0.80
50 → 75
+50% increase · ×1.5
200 → 150
−25% decrease · ×0.75
How it works
Use this percent increase calculator to quickly compute the percentage change between two values, showing how much a number has grown or shrunk relative to its starting point.
% change · ((new − old) / |old|) × 100
multiplier · new / old
A positive result is an increase, a negative result is a decrease. A multiplier of 1 means no change; 2 means doubling; 0.5 means halving.
Related guides
- Percent Change Formula How to calculate percent change between two numbers, handling increases and decreases.
- How to Calculate Percentage Increase Step by step with three worked examples (price, salary, and traffic).
- Percentage Increase Formula What each piece of the formula means and why the old value is the base.
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Frequently asked questions
Percentage change = ((new − old) / old) × 100. A positive result is an increase, a negative result is a decrease. We divide by the absolute value of the original so the sign of the result reads naturally even when the starting value is negative.
Percent change from zero is mathematically undefined — there's no baseline to compare against. Any non-zero new value would represent “infinite” percent change. We flag this case rather than printing a misleading number; report the absolute change instead.
If a rate goes from 4% to 6%, that's a 2 percentage point increase, but a 50% relative increase. Use percentage points when comparing two rates or proportions; use percentage change for everything else (prices, populations, scores, weights, etc.).
Yes — mathematically they're the same calculation. We label the result “increase” for positive change and “decrease” for negative change so the meaning is unambiguous, but a 20% decrease and a −20% increase are the same thing.
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