Percentage vs. percentage change
20% of 80 asks for a portion and equals 16. A change from 80 to 100 compares two values and equals (100 − 80) ÷ 80 × 100 = 25%. This calculator handles the portion, not the two-value comparison.
💯 Percentage Calculator
Calculate a percentage of a non-negative number instantly. Use it to estimate discount amounts, sales tax, tips, commissions, grades, budgets, and everyday percentage values.
🧮 Percentage of a Number
Enter a value and percentage to get the answer instantly.
Percentages above 100% and decimal percentages are supported.
📝 Enter a value and percentage to see the result.
Financial estimate disclaimer
This calculator provides a mathematical estimate for general planning. It does not determine final prices, tax liability, legal obligations, or financial advice. Verify rates and transaction details with the relevant authority or a qualified professional.
📘 How the Percentage Calculator Works
This calculator answers one common percentage question: What is X percent of Y?
✓ Enter the original value or amount.
✓ Enter the percentage you want to calculate.
✓ Choose Number, US, or CA as the result format.
✓ View the percentage value instantly.
🧮 Percentage formula
Percentage Value = Value × (Percentage ÷ 100)
Result = Value × Percentage ÷ 100
Value = the original number or amount
Percentage = the percent being calculated
Result = the calculated portion of the original value
🎯 When to Use This Calculator
- ✓ Calculate the discount amount on a sale.
- ✓ Estimate a U.S. sales-tax amount.
- ✓ Calculate GST, HST, PST, or QST amounts.
- ✓ Work out a restaurant tip.
- ✓ Calculate a sales commission.
- ✓ Find a percentage of points or marks.
- ✓ Calculate a business allocation.
- ✓ Divide income into budget categories.
- ✓ Find a percentage of an investment value.
- ✓ Check coupon and promotional savings.
- ✓ Calculate donation or contribution amounts.
🧭 Which Percentage Problem Are You Solving?
Start by identifying what the question asks for. This calculator directly finds a percentage portion of one base value; for an increase or decrease, it finds the adjustment amount but does not add or subtract it automatically.
| Problem type | Example question | Formula meaning | Typical use |
|---|---|---|---|
| Find a percentage of a number | What is 25% of 80? | 80 × 0.25 = 20 | Portions, allocations, or part of a total |
| Find an increase amount | How much is a 25% increase on 80? | 80 × 0.25 = 20 | Markup or budget adjustment; add 20 to the base yourself |
| Find a decrease amount | How much is a 20% decrease on 120? | 120 × 0.20 = 24 | Discount or reduction; subtract 24 from the base yourself |
⚠️ Common Percentage Mix-Ups
Percentage change vs. percentage points
A rate rising from 40% to 50% increases by 10 percentage points. Relative to the original 40%, the increase is 25%. Percentage points use direct subtraction; percentage change uses the starting rate as the base.
Increase by 20% vs. is 20% of
20% of 100 is 20. Increasing 100 by 20% means calculating that 20 and then adding it to the original value, giving 120.
Why +20% and −20% do not cancel
100 increased by 20% becomes 120. A 20% decrease from 120 is 24, so the result is 96. The percentages use different base values.
Reverse percentage is division
If a value became 100 after a 25% increase, the original was 100 ÷ 1.25 = 80—not 100 − 25 = 75. Reverse percentage is not provided by this two-field interaction.
🔎 Quick Percentage Decision Guide
“of”
Use this calculator: find X% of one value.
“what percent”
Needs part ÷ whole × 100; this interaction does not provide that mode.
“increase/decrease by”
Use this calculator for the adjustment amount, then add or subtract it.
“from A to B”
Needs percentage change between two values; not provided here.
“percentage points”
Subtract the two percentage rates directly; do not use this calculator as a change calculator.
“after an X% increase/decrease”
Needs reverse percentage division; not provided here.
💡 Worked Examples for Different Uses
Each example below calls the same production calculation used by the interactive calculator.
Find a percentage of a number
What is 25% of 80?
80 × 25 ÷ 100 = 20
The calculated portion is 20.
Find a discount amount
What is a 15% discount on 200?
200 × 15 ÷ 100 = 30
The discount is 30; subtract it from 200 to get 170.
Find an increase amount
How much is a 25% increase on 80?
80 × 25 ÷ 100 = 20
The increase is 20; add it to 80 to get 100.
✅ Scope and Limitations
Good fits
- • Discount and markup amounts
- • Tax-rate and tip amount checks
- • A known percentage of points, marks, or a budget
- • Single-period growth or decline adjustment amounts
Use a different calculation
- • Compound growth across multiple periods
- • APR, APY, probability, or weighted averages
- • Percentage change or percentage-point interpretation
- • Reverse percentage and original-value recovery
🌎 Percentage Calculations in the United States and Canada
🇺🇸 Percentage Calculator for U.S. Users
Choose US when calculating a percentage of an amount in USD. The calculator can help estimate sales-tax amounts, discounts, tips, commissions, and budget allocations.
🧾 U.S. sales-tax example
If a purchase costs $75 USD and the sales-tax rate is 8%, then 8% of $75 is $6.
The calculator shows the tax amount. Add it to the original price to estimate the checkout total.
⚠️ Sales-tax rates and product taxability vary by state and local jurisdiction.
🇨🇦 Percentage Calculator for Canadian Users
Choose CA when calculating a percentage of an amount in CAD. The calculator can help estimate GST, HST, PST, QST, discounts, tips, commissions, and budget allocations.
🧾 Canadian HST example
To calculate 13% HST on a $100 CAD taxable amount, 13% of $100 is $13.
The calculator shows the tax amount. Add it to the original amount to estimate the after-tax total.
⚠️ Canadian tax rates and rules vary by province, territory, and purchase type.
📚 Method, Source, and Review
- Method
- Percentage value = original value × percentage ÷ 100. Calculations retain full numeric precision until the result is formatted for display.
- Calculation version
- Percentage Calculator V2
- Last reviewed
- August 15, 2026
- Maintained by
- FigureNorth Editorial Team
- Review status
- Educational percentage calculator for non-negative finance and everyday planning inputs.
❓ Percentage Calculator FAQ
What is the difference between a percentage and percentage change?
A percentage of a value finds a portion of one base, such as 20% of 80 = 16. Percentage change compares an old value with a new value using (new − old) ÷ old × 100. This calculator performs the first operation, not the two-value change calculation.
What are percentage points?
Percentage points measure the direct difference between two percentages. A rate moving from 40% to 50% rises by 10 percentage points, but its relative percentage increase is 25% because 10 ÷ 40 × 100 = 25%.
Why does increasing by 20% and then decreasing by 20% not return to the starting value?
The two operations use different bases. Increasing 100 by 20% gives 120. Decreasing 120 by 20% subtracts 24, leaving 96 rather than 100.
How do I find the original number before a percentage increase?
Use reverse percentage division, which this interaction does not calculate directly. If a value became 100 after a 25% increase, divide 100 by 1.25 to get the original value of 80; subtracting 25 would incorrectly give 75.
Can percentages be greater than 100%?
Yes. The production calculator accepts non-negative percentages up to its supported limit. For example, 150% of 80 is 120, which is greater than the base value.
Can percentage change be negative?
Yes, a separate percentage-change calculation can be negative when a new value is below the starting value. This calculator does not calculate percentage change and does not accept a negative percentage input; enter a positive rate to find the size of a decrease, then subtract that amount manually.
What happens when the starting value is zero?
For this calculator's supported operation, any non-negative percentage of zero equals zero. A percentage change from a starting value of zero is undefined because its formula divides by the starting value, and that separate operation is not provided here.