Percentage Increase & Decrease Calculator
Calculate percentage growth, price discounts, profit margins, and value differences with instant formula breakdowns.
Percentage Change (From A to B)
Absolute difference: +75
What is X% of Y?
18% of 4500 = 810
X is what percent of Y?
(35 ÷ 140) × 100 = 25%
Add or Deduct X% from Base
Adjustment: +150.00
Complete Guide to Percentage Change, Growth Rates & Margin Mathematics
Percentages are the universal standard for quantifying growth, economic inflation, retail discounts, investment returns (ROI), and statistical variance. Knowing how to calculate percentage increase and decrease accurately prevents common errors in business pricing, equity evaluations, and scientific reports.
Core Percentage Change Formula
Percentage change measures the relative shift between an original baseline value (A) and a new value (B):
Relative Difference: Δ = Final Value (B) - Initial Value (A)
Percentage Change: % = (Δ / |Initial Value (A)|) × 100
Percent of a Whole: % = (Part / Total) × 100
Reverse Percentage: Base = Final / (1 ± Rate)
Percentage (%) vs. Percentage Points (pp)
A widespread financial misconception confuses percentage growth with percentage point changes:
- • If interest rates rise from 10% to 12%:
- • The Percentage Point increase is 2 pp (200 bps)
- • The Percentage Change in rate is
((12 - 10) / 10) × 100 = +20%
Retail Markup vs. Profit Margin Conversion Table
| Cost Price (CP) | Markup Percentage | Selling Price (SP) | Profit Margin (%) | Gross Profit |
|---|---|---|---|---|
| ₹100 | 25% Markup | ₹125 | 20.0% Margin | ₹25 |
| ₹100 | 50% Markup | ₹150 | 33.3% Margin | ₹50 |
| ₹100 | 100% Markup (Keystone) | ₹200 | 50.0% Margin | ₹100 |
| ₹100 | 300% Markup | ₹400 | 75.0% Margin | ₹300 |
Frequently Asked Questions (FAQ)
Why does a 50% price loss require a 100% gain to break even?
If a ₹100 stock drops by 50%, its new value is ₹50. To return to the original ₹100, the stock must gain ₹50 on a ₹50 base, which represents a (50 / 50) × 100 = 100% gain. Asymmetrical percentage recoveries are a cornerstone of financial risk management.
What is the difference between markup and gross profit margin?
Markup is the percentage added to the Cost Price (Profit / Cost). Profit Margin is the percentage of the final Selling Price that is profit (Profit / Selling Price).
How do I calculate negative percentage change when original numbers are negative?
Always take the absolute value of the denominator: ((Final - Initial) / |Initial|) × 100. This guarantees mathematically consistent directional indicators for corporate balance sheet losses.