Use this free All-in-One Percentage Calculator to answer common percentage questions in simple everyday language.
Choose the section that matches your question. Each section works on its own, so you do not need to use every box.
Find a Percent of a Number
Example: What is 20% of 100?
Find What Percent
Example: 20 is what percent of 100?
Price Went Up or Down
Example: A price went from $80 to $100. This shows the percentage increase or decrease.
Add a Percent
Example: Add 15% to $50. This is helpful for increases, markups, fees, or estimated added costs.
Take a Percent Off
Example: Take 20% off $100. This is helpful for discounts, sale prices, coupons, and markdowns.
How This Percentage Calculator Helps
This calculator helps answer common percentage questions without forcing you to choose from confusing math terms. Each section is written like a real-life question, so you can pick the one that matches what you are trying to calculate.
You can use it for shopping, discounts, price changes, markups, savings, bills, budgeting, tips, raises, and quick everyday math.
Simple Percentage Examples
If you want to know what 20% of 100 is, use the “Find a Percent of a Number” section. Enter 20 as the percentage and 100 as the number. The answer is 20.
If you want to know what percent 20 is out of 100, use the “Find What Percent” section. Enter 20 as the first number and 100 as the second number. The answer is 20%.
If a price went from $80 to $100, use the “Price Went Up or Down” section. The calculator shows that the price increased by 25%.
Common Ways to Use This Calculator
Discounts and Sale Prices
Use “Take a Percent Off” to estimate how much a discount removes from the original price and what the sale price may be.
Price Increases
Use “Add a Percent” to estimate markups, fees, increases, or added costs.
Before and After Changes
Use “Price Went Up or Down” to compare an old value and a new value.
Everyday Percent Questions
Use the first two sections for simple questions like “What is 10% of 200?” or “50 is what percent of 250?”
How to Use the Results
Each result is based only on the numbers entered in that section. Empty sections do not affect the other sections. You can calculate one percentage question, reset that section, reset the whole calculator, or use a different section for another question.
Results are estimates only. Important numbers should be double-checked, especially when percentages are being used for taxes, payroll, loans, legal documents, business decisions, or financial planning.
Percentage Calculator FAQs
Do I have to use every section?
No. Each section works by itself. Use only the section that matches your question.
What is a percentage?
A percentage is a number expressed as part of 100. For example, 25% means 25 out of 100.
How do I calculate a percentage of a number?
Multiply the number by the percentage divided by 100. For example, 20% of 100 is 20.
How do I calculate a discount?
Use the “Take a Percent Off” section. Enter the starting price and the discount percentage to estimate the savings and final price.
How do I calculate a price increase?
Use the “Add a Percent” section if you know the percent being added, or use “Price Went Up or Down” if you know the old and new prices.
Can percentages be negative?
Yes. A negative percentage change usually means the new value is lower than the original value.
Are the results exact?
Results are estimates based on the numbers entered. Rounding and real-world details may affect final totals.