Percentage Calculator – Calculate % Increase, Decrease, Difference & Discounts
Calculate percentage of a number, percentage increase or decrease, price discounts, marks percentages, and reverse pre-tax values with instant step-by-step results.
15% of 5,000 equals 750
How to Calculate Percentages: Formulas & Real-World Examples
Step-by-step mathematical formulas for common academic, business, and shopping calculations:
1. Percentage of a Number (X% of Y)
BasicExample: What is 20% of 500?
Result = (20 / 100) × 500 = 100
2. Percentage Increase
GrowthExample: 500 to 600 percentage increase:
[ (600 - 500) / 500 ] × 100 = +20.0%
3. Percentage Decrease
DeclineExample: 600 to 500 percentage decrease:
[ (600 - 500) / 600 ] × 100 = -16.67%
4. Percentage Difference
ComparisonUsed to compare two separate values without designating one as a baseline.
5. Discount Calculator
ShoppingExample: ₹1,000 with 20% discount:
₹1,000 - ₹200 savings = ₹800 final price
6. Reverse Percentage
Pre-TaxExample: ₹1,180 with 18% GST included:
Original Base = 1180 / 1.18 = ₹1,000
Quick Reference Percentage Cheat Sheet
Instant percentage lookups for standard benchmark numbers:
| Value | 10% | 15% | 20% | 25% | 50% |
|---|---|---|---|---|---|
| ₹500 | ₹50 | ₹75 | ₹100 | ₹125 | ₹250 |
| ₹1,000 | ₹100 | ₹150 | ₹200 | ₹250 | ₹500 |
| ₹5,000 | ₹500 | ₹750 | ₹1,000 | ₹1,250 | ₹2,500 |
| ₹10,000 | ₹1,000 | ₹1,500 | ₹2,000 | ₹2,500 | ₹5,000 |
| ₹50,000 | ₹5,000 | ₹7,500 | ₹10,000 | ₹12,500 | ₹25,000 |
Frequently Asked Questions
Clear answers regarding percentage formulas, increase/decrease calculations, discount savings, and reverse percentages.
How do you calculate percentage of a number?
To find the percentage of a number, convert the percentage to a decimal by dividing by 100, then multiply by the total number. Formula: Result = (Percentage Rate ÷ 100) × Total Value. For example, 20% of 500 = (20 ÷ 100) × 500 = 100.
How is percentage increase calculated?
To calculate percentage increase: Subtract the original value from the new value, divide the difference by the original value, and multiply by 100. Formula: Percentage Increase = [ (New Value - Original Value) ÷ Original Value ] × 100. For example, from 500 to 600 is [ (600 - 500) ÷ 500 ] × 100 = 20% increase.
How is percentage decrease calculated?
To calculate percentage decrease: Subtract the new value from the original value, divide the difference by the original value, and multiply by 100. Formula: Percentage Decrease = [ (Original Value - New Value) ÷ Original Value ] × 100. For example, from 600 to 500 is [ (600 - 500) ÷ 600 ] × 100 = 16.67% decrease.
How do you calculate discount and final price?
To find a discounted price: Multiply the original retail price by the discount percentage to get the savings amount, then subtract the savings from the original price. For example, a ₹1,000 item with a 20% discount gives ₹200 savings (1000 × 0.20), leaving a final price of ₹800.
What is reverse percentage and how is it used?
Reverse percentage is used to find the original amount before a tax, discount, or price hike was applied. For example, if a product costs ₹1,180 including 18% GST, the original pre-tax price is calculated as ₹1,180 ÷ (1 + 0.18) = ₹1,000.
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