A free percentage calculator that answers 6 questions from 2 numbers at once, with the formulas worked out.
Type 2 numbers and get every percentage answer at once: X% of Y, what percent, the change and the difference.
Your numbers
Type any 2 numbers. The calculator answers every percentage question they can ask at once, so there's no mode to pick.
Your result
Fill in the fields above to see your result.
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This free percentage calculator answers every question 2 numbers can ask at once: X% of Y, what percent X is of Y, the percent change, the percent difference, and Y plus or minus X%.
There's no mode to pick and no formula to remember. You type 2 numbers and read the answer you came for.
I built it because every percentage site makes you choose the right box first, and half the time you're not sure which question you're asking. Here, all 6 answers sit side by side.
Below are the formulas, a worked example, and the mistakes that trip up even good spreadsheets.
TL;DRKey takeaways
What is a percentage calculator?
A percentage calculator works out parts of a hundred. "Percent" means per hundred, so 15% is 15 out of every 100.
The same 2 numbers can ask 6 different questions, and each one has its own formula. This calculator runs all 6 on the numbers you type.
How to use the percentage calculator
You only type 2 numbers.
Negative numbers work too, for a loss or a drop in temperature.
A worked example
Here's the example the calculator loads when you press Try an example: X is 15 and Y is 80.
- Formula
- 15 ÷ 100 × 80
- Answer
- 12
- Formula
- 15 ÷ 80 × 100
- Answer
- 18.75%
- Formula
- (80 − 15) ÷ 15 × 100
- Answer
- +433.33%
- Formula
- 65 ÷ 47.5 × 100
- Answer
- 136.84%
- Formula
- 80 × 1.15
- Answer
- 92
- Formula
- 80 × 0.85
- Answer
- 68
The change and the difference give different answers on purpose. The change asks how far you moved from where you started. The difference asks how far apart 2 numbers are when neither is the start.
Which percentage do you need?
These everyday questions each match one card.
A tip or a tax
"What's 18% of a $64 bill?" is X% of Y. Type 18 and 64.
A test score
"I got 42 out of 50, what's my percent?" is X is what percent of Y. Type 42 and 50 for 84%.
A raise or a price rise
"My pay went from $4,000 to $4,400" is the percent change: 10%. The hourly to salary calculator turns either into an hourly rate.
Comparing 2 offers
"Is $410 or $455 the better quote?" is the percent difference, about 10.4%, because neither is the starting point.
Mistakes to avoid
These are the slips that turn a right number into a wrong decision.
- Dividing a change by the new number instead of the old one
- Adding percentages that apply one after another (two 20% discounts are 36% off, not 40%)
- Reading a fall and a rise as equal (down 50% then up 50% leaves you at 75%)
- Mixing up percent and percentage points (5% to 7% is 2 points, or a 40% rise)
When a number moves twice, run each step on the calculator in turn.
Percentages in money
Percentages decide what money does over time. A 7% return doubles money in about 10 years, and a 1% yearly fee on that return takes about a quarter of what you'd have after 30.
The compound interest calculator shows that on a chart, and the discount calculator does the percent-off sums for shopping.
Percentages in marketing
Most marketing numbers are percentages, and each has a plain formula:
- Formula
- Clicks ÷ views × 100
- Example
- 40 clicks from 2,000 views is 2%
- Formula
- Sales ÷ visitors × 100
- Example
- 30 sales from 1,500 visitors is 2%
- Formula
- (This year − last year) ÷ last year × 100
- Example
- 12,000 visitors after 10,000 is 20%
- Formula
- (New rate − old rate) ÷ old rate × 100
- Example
- 2.5% against 2% is a 25% lift
A rate going from 2% to 2.5% rises half a percentage point, which is a 25% lift. Say which one you mean, since both describe the same change.
Each line is the percent change or the "what percent" answer, so the calculator above does all of them.
Who is the percentage calculator for?
It's for anyone who needs a percent fast, and these tools pick up where it stops.
- Discount calculator – for sale prices, stacked discounts and tax
- Unit price calculator – for which size is the better buy
- Compound interest calculator – for percentages that grow every year
- Currency converter – for prices in another currency
- Card fees abroad calculator – for the percent your card charges overseas
Type your 2 numbers, and every answer is waiting.
Plan your money with your AI
Take your numbers further in
Percentage Calculator FAQs
Questions about the percentage calculator? Here's what to know.
A percentage calculator works out parts of a hundred from 2 numbers. This free one answers 6 questions at once: X% of Y, what percent X is of Y, the change, the difference, and Y plus or minus X%.
Divide the percent by 100 and multiply by the number. 15% of 80 is 15 ÷ 100 × 80, which is 12.
Divide the part by the total and multiply by 100. 15 out of 80 is 15 ÷ 80 × 100, which is 18.75%.
Subtract the old number from the new one, divide by the old one and multiply by 100. From 15 to 80 is 65 ÷ 15 × 100, an increase of 433.33%.
Percent change measures a move from a starting number. Percent difference compares 2 numbers against their average, so it's the same whichever comes first.
Multiply by 1 plus the percent as a decimal. 80 plus 15% is 80 × 1.15, which is 92.
Multiply by 1 minus the percent as a decimal. 80 minus 15% is 80 × 0.85, which is 68.
The rise starts from a smaller number. 100 down 50% is 50, and 50 up 50% is only 75.
A percentage point is the plain gap between 2 percents. A rate going from 5% to 7% rises 2 points, which is a 40% increase.
Yes, for a change or a comparison. 80 is 533.33% of 15, and going from 15 to 80 is a 433.33% increase.
Yes, it's free with no sign-up. It runs in your browser, and your numbers stay on your device.
I did. I'm Navid Moazzez, and I made the percentage calculator as one of my free tools on navid.me.
More about me.
Navid Moazzez
AI business strategist & AI OS builder
Navid Moazzez helps creators and founders master AI and build their own AI Operating System (AI OS) to automate their business and life.
Navid.me is reader-supported. When you buy through links on this site, I may earn an affiliate commission. Learn more.
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