Here is how to calculate percentage in one line: divide the part by the whole and multiply by 100. If you scored 437 out of 500, then 437 ÷ 500 = 0.874, and 0.874 x 100 = 87.4 percent.
That single rule covers marks, attendance, discounts and almost every form that asks for a percentage. This guide shows it on paper, then key by key on a basic calculator and on a phone, and ends with the slips behind most wrong answers.
At a glance
Formula
Percentage = part ÷ whole x 100Marks example
437 out of 500 = 87.4%Safe key order
part ÷ whole = then x 100 =X% of a number
X ÷ 100 x number, so 18% of 2400 = 432Find the whole
part ÷ percent x 100, so 45 is 15% of 300
Percentage = (Part ÷ Whole) x 100
Part is the amount you have, such as marks scored or classes attended. Whole is the full amount, such as maximum marks or classes held.
The percentage calculator formula, explained
Percent means per hundred. When you ask what percent 437 is of 500, you are asking how many out of every 100 it would be if the whole were scaled down to 100. Dividing 437 by 500 tells you the share for every 1 unit (0.874). Multiplying by 100 turns that share into a figure per hundred (87.4).
Every percentage question is one of three shapes, and the same formula rearranges to answer each:
| You know | You want | Do this | Example |
|---|---|---|---|
| Part and whole | Percent | part ÷ whole x 100 | 437 of 500 = 87.4% |
| Percent and whole | Part | percent ÷ 100 x whole | 18% of 2400 = 432 |
| Percent and part | Whole | part ÷ percent x 100 | 45 is 15% of 300 |
- Write down the part, for example your total marks.
- Write down the whole, for example the maximum marks.
- Divide the part by the whole.
- Multiply the answer by 100.
- Round the result to two decimals and add the percent sign.
How to calculate percentage in calculator: basic model
Whether you are asking how to get percentage in calculator sums, how to find or check it, how to do it or how to calculate percentage with calculator keys and how to use the % button, the order below never changes. On a plain desk calculator, it works on every model, old or new:
- Type 437.
- Press ÷.
- Type 500.
- Press = and read 0.874.
- Press x, type 100, press = and read 87.4.
Many desk models also let you skip the last step: 437 ÷ 500 % shows 87.4 straight away. The % key does not behave the same on every brand, so test it once with a sum you already know, such as 50 ÷ 200 %, which should give 25. If it gives 0.0025 or something odd, stick to the x 100 method.
How to do percentage on a mobile calculator
Phone calculators usually treat % as “divide by 100”. That makes finding a part very quick, but finding a percent needs the long way.
- To get a percent from marks: type 437 ÷ 500 x 100 and press =. Result 87.4.
- To take a percent of a number: type 18 % x 2400 and press =. The phone reads 18 % as 0.18, so the result is 432.
- To check the % key: type 50 % and press =. If it shows 0.5, your phone uses the divide by 100 behaviour.
If the screen is small, use the scientific view in landscape so you can see the full line before pressing =. For the same steps in Hinglish, see percentage kaise nikale.
Worked examples with real numbers
Attendance. You attended 52 of 64 classes. 52 ÷ 64 = 0.8125, times 100 = 81.25 percent.
One subject. 68 out of 80 in a practical paper: 68 ÷ 80 x 100 = 85 percent.
Full mark sheet. Six papers with marks 71, 64, 88, 59, 77 and 82 out of 100 each. Total 441 out of 600. 441 ÷ 600 x 100 = 73.5 percent.
Finding the whole. A hostel says 45 seats are 15 percent of its intake. Intake = 45 ÷ 15 x 100 = 300.
For a mark sheet with many rows, the marks percentage calculator adds the papers for you. For your attendance shortfall, the attendance calculator also tells you how many classes you still need.
How to remove percentage in calculator sums
Students ask this for two different jobs, and they need different keys.
Taking a percent off a number. To cut 15 percent from 3000, multiply by 0.85: 3000 x 0.85 = 2550. Some desk calculators accept 3000 − 15 % and show 2550 too, but the multiply method never misleads.
Getting back the original after a percent was added. If 18 percent was added and the bill now reads 1180, divide by 1.18: 1180 ÷ 1.18 = 1000. Subtracting 18 percent of 1180 instead gives 967.6, which is wrong, because the 18 percent was worked out on 1000 and not on 1180.
The same thinking sits behind the percentage decrease calculator, which works on the original value.
Quick table: common fractions as percentages
Knowing these by heart lets you check a calculator answer at a glance.
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333 | 33.33% |
| 2/3 | 0.667 | 66.67% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 1/10 | 0.1 | 10% |
| 1/20 | 0.05 | 5% |
| 1/25 | 0.04 | 4% |
Slips that give the wrong percentage
| Slip | What goes wrong | Better way |
|---|---|---|
| Typing whole ÷ part | 500 ÷ 437 gives 1.14, which is upside down | The smaller, scored number goes first |
| Forgetting x 100 | 0.874 is a decimal, not 87.4% | Multiply by 100 at the end |
| Trusting the % key blindly | Brands handle it differently | Test it with 50 ÷ 200 % first |
| Using the wrong maximum | Practical or internal marks left out of the total | Copy the maximum printed on the mark sheet |
| Averaging subject percents | Papers with bigger maximums get under-counted | Add marks first, then divide once |
Where to use the calculator above instead
The tool placed above this guide saves the key presses. Its first two modes match the first two rows of the shapes table: X percent of Y, and X as a percent of Y. Its other modes cover sums this page only touches on: the increase, change and difference between two numbers. The percentage calculator hub lists them all, with mental shortcuts for when you have no device at hand.
Questions students ask
How to calculate percentage of marks on a calculator?
Type your total marks, press ÷, type the maximum marks, press x 100 and then =. For 441 out of 600 the screen shows 73.5.
How to find percentage on calculator using the % key?
On many desk calculators, type part ÷ whole and then press %, for example 437 ÷ 500 %. Test the key first with 50 ÷ 200 %, which should give 25, because some models handle it differently.
How to calculate percentage on mobile calculator?
Phones treat % as divide by 100, so type the full sum: part ÷ whole x 100 =. To take 18 percent of 2400 you can type 18 % x 2400 = and get 432.
What is the percentage formula in calculator terms?
Part ÷ whole x 100. Every percent sum on a calculator is this formula or a rearranged form of it.
How to get the original amount after a percent was added?
Divide by 1 plus the rate as a decimal. If 18 percent was added and the total is 1180, the original is 1180 ÷ 1.18 = 1000.
How to take out percentage in calculator for a discount?
Multiply the amount by 1 minus the rate. A 15 percent cut on 3000 is 3000 x 0.85 = 2550.