Percentage Calculator
Fast and ergonomic tool to calculate percentages, percentage change, sales discounts, and reverse percentages.
boltInstant Calculation
%
Calculated Result
30
(20 ÷ 100) × 150 = 30
Visual proportion of 20%20.0%
Percentage Calculations, Increases, & Discount Guide
Percentages express proportions as fractions of 100, used everywhere from sales discounts to rate changes.
1How to Find a Percentage of a Number
To find a percentage of any number, divide the percentage by 100 to convert it into a decimal rate, then multiply it by the total number.
Formula: Value = (Percentage ÷ 100) × Total
Example: What is 20% of 150? (20 ÷ 100) × 150 = 0.20 × 150 = 30.
2How to Calculate What Percentage One Number is of Another
When you know the partial amount and the total, divide the part by the total and multiply by 100 to convert to a percentage.
Formula: Percentage = (Part ÷ Total) × 100
Example: You scored 45 out of 60 on an exam. (45 ÷ 60) × 100 = 0.75 × 100 = 75%.
3How to Calculate Percentage Increase or Decrease
Percentage change measures the relative difference between an original starting value and a new final value.
Formula: % Change = ((New Value - Original Value) ÷ Original Value) × 100
Example: An item price goes from $100 to $125. ((125 - 100) ÷ 100) × 100 = +25% increase.
Quick Percentage Reference Cheat Sheet
| Total | 10% | 15% | 20% | 25% | 50% |
|---|---|---|---|---|---|
| $10 | $1.00 | $1.50 | $2.00 | $2.50 | $5.00 |
| $50 | $5.00 | $7.50 | $10.00 | $12.50 | $25.00 |
| $100 | $10.00 | $15.00 | $20.00 | $25.00 | $50.00 |
| $500 | $50.00 | $75.00 | $100.00 | $125.00 | $250.00 |
Frequently Asked Questions
Subtract the old value from the new value, divide by the old value, and multiply by 100.