Free Online Percentage Calculator, Increase, Discount, Tax & Tip
Work out any percentage question in one place. Find a percentage of a number, the change between two numbers, a discount and what you save, tax added or removed, a tip, a margin, or a grade out of a total. Every answer shows the working underneath, so you can check it or copy the method.
What is X% of Y?
The everyday one, a percentage of a number.
X is what percentage of Y?
Turn a part and a total into a percentage.
Percentage increase
How much bigger the new value is.
Percentage decrease
How much smaller the new value is.
Percentage change
Up or down, it works out which.
Percentage difference
A comparison with no direction to it.
Add X% to a number
Mark something up.
Subtract X% from a number
Take something off.
Find the original number
Work backwards from the result.
Discount calculator
What you pay and what you save.
Tax calculator
Add tax on, or take tax back out.
Tip calculator
Tip, total and each person's share.
Profit and loss
Cost against selling price.
Commission calculator
The cut, and what is left.
Grade & exam percentage
Any number of subjects, with an optional grade.
| Subject | Obtained | Total | Remove |
|---|
Percentage converter
Percent, decimal and fraction, all four ways.
Split a number by percentages
Divide a total into shares.
| Label | Percentage | Remove |
|---|
| When | Calculator | Calculation | Result | Actions |
|---|
Number format
Currency
The symbol appears only on the calculators where money is involved: discount, tax, tip, profit and loss, commission and split. A percentage is the same number in every country.
Appearance
Results
History
Your data
Settings, history and favorites are stored only in this browser. There is no copy anywhere else, so these cannot be undone.
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How to Use the Percentage Calculator
Six steps, and nothing leaves your computer.
Seventeen of them, grouped into basics, change, money and tools. Only the one you choose is on screen.
Each one asks for two or three numbers in plain language. Answers appear as you type, and there is nothing to submit.
Every result comes with the formula filled in, so you can check it rather than trust it.
One button copies the result. Turn on auto-copy in Settings and it happens by itself.
Frequent sums, such as a standard commission or your usual tax rate, can be saved to Favorites and reloaded in one click.
Decimal places, thousands separators, currency, theme and full screen are all in Settings, and are remembered on this device.
Which Calculator Do You Need?
Find your question on the left, and the tab that answers it is on the right.
| If you are asking | Use this tab | You get |
|---|---|---|
| What is 20% of 500? | Basic Percentage | 100 |
| 45 out of 60 is what percentage? | What Percentage | 75% |
| The price went from 500 to 600 | Percentage Increase | 20% increase |
| Sales fell from 600 to 500 | Percentage Decrease | 16.67% decrease |
| How different are 80 and 100? | Percentage Difference | 22.22% |
| What is 15% off £80? | Discount | £68, saving £12 |
| It cost 120 including 20% tax | Tax | 100 before tax |
| It is 120 after a 20% rise. What was it? | Reverse Percentage | 100 |
| Bought at 60, sold at 100 | Profit & Loss | 66.67% profit, 40% margin |
| Split a £90 bill three ways with 10% tip | Tip | £33 each |
| My marks across six subjects | Grade | Percentage and grade |
| What is 0.375 as a percentage? | Percentage Converter | 37.5%, or 3/8 |
The reason there are 17 calculators rather than one is that these are genuinely different sums. "What is 20% of 500" and "500 became 600, by how much" both involve a percentage and two numbers, but they use different formulas and give different answers. A single input box has to guess which one you meant, and when it guesses wrong you have no way of knowing. Here each question gets its own panel, its own labels and its own visible working.
The Formulas, With Worked Examples
Worth knowing, so you can do these without a calculator next time.
| Question | Formula | Example |
|---|---|---|
| What is P% of X? | X × P ÷ 100 |
20% of 500 = 500 × 20 ÷ 100 = 100 |
| X is what percent of Y? | X ÷ Y × 100 |
100 of 500 = 100 ÷ 500 × 100 = 20% |
| Percentage increase | (New − Old) ÷ Old × 100 |
500 to 600 = 100 ÷ 500 × 100 = 20% |
| Percentage decrease | (Old − New) ÷ Old × 100 |
600 to 500 = 100 ÷ 600 × 100 = 16.67% |
| Percentage difference | |A − B| ÷ ((A + B) ÷ 2) × 100 |
80 and 100 = 20 ÷ 90 × 100 = 22.22% |
| Add P% to X | X × (1 + P ÷ 100) |
500 + 20% = 500 × 1.2 = 600 |
| Subtract P% from X | X × (1 − P ÷ 100) |
500 − 20% = 500 × 0.8 = 400 |
| Original before a P% rise | Final ÷ (1 + P ÷ 100) |
120 after +20% = 120 ÷ 1.2 = 100 |
| Original before a P% fall | Final ÷ (1 − P ÷ 100) |
80 after −20% = 80 ÷ 0.8 = 100 |
| Profit percentage | Profit ÷ Cost × 100 |
Cost 60, sell 100 → 40 ÷ 60 × 100 = 66.67% |
| Loss percentage | Loss ÷ Cost × 100 |
Cost 100, sell 60 → 40 ÷ 100 × 100 = 40% |
| Percentage to fraction | P ÷ 100, then simplify |
25% = 25/100 = 1/4 |
Where Percentages Usually Go Wrong
The arithmetic is easy. Knowing which sum to do is not.
Key Features & Capabilities
A calculator that explains itself.
Basic percentages, increase, decrease, change, difference, add, subtract, reverse, discount, tax, tip, profit and loss, commission, grade, converter and split, all in one place.
No submit button and no page reloads. Results and the working update on each keystroke.
Every answer displays the formula with your own numbers in it, so you can verify the sum or learn it.
Each result has a copy button, with an optional auto-copy for repetitive work.
Recent calculations are kept automatically, and the ones you repeat can be saved with a name of your choosing.
Nine currencies plus a custom option, applied only to the calculators where money is actually involved.
Any number of subjects and a choice of grading scales: South Asian boards, US letters, UK 9 to 1, 4.0 GPA, or percentage only.
No accounts, no uploads, no server. Every number stays in your browser, and Settings can wipe all of it.
About the Percentage Calculator
Percentages are the arithmetic most of us actually use. A discount in a shop window, a tax line on an invoice, a pay rise, an exam result, a commission split. They are all the same idea wearing different clothes. The sums are simple enough on paper, which is precisely why they get done in a hurry and get done wrong. This calculator does them properly and, just as importantly, shows the line of working so you can see what it did.
There are seventeen calculators here rather than one, because the questions are genuinely different. "What is 20% of 500" and "500 became 600, by what percentage" both involve a percentage and two numbers, but the formula is not the same one. Guessing which sum a single input box is doing is how people end up confidently wrong, so each question gets its own panel, its own labels and its own visible formula.
Some of these tools exist mainly to prevent a specific mistake. Reverse percentage exists because taking 20% off a total does not undo adding 20% to it. Tax removal exists because the right operation is a division, not a subtraction. Percentage difference exists because it is not the same thing as percentage change. In each case the tool gives the correct answer and explains, in a line, why the obvious method fails.
Everything runs in your browser. There is no account to make, no data to upload and no server that ever sees a number you type: settings, history and favorites are stored in your own local storage, and one button in Settings removes all of it. That keeps the calculator fast, private and usable with the connection off.
Frequently Asked Questions
The questions behind the questions.