how to get percentage using calculator

What does percentage actually mean?

A percentage is a way to express a value “out of 100.” So 50% means 50 out of 100, 25% means 25 out of 100, and 100% means the entire amount. Once you understand this, getting percentages with a calculator becomes very simple.

Most people search for how to get percentage using calculator because they need practical answers quickly: discount prices, exam scores, tax calculations, tips, or business growth numbers. The good news is you only need a few formulas.

How to get percentage using calculator: the 3 core calculations

1) Find a percentage of a number

Use this when you want to know values like “20% of 450” or “15% tip on 1,200.”

• Step 1: Divide the percentage by 100.
• Step 2: Multiply by the number.
• Formula: (percentage ÷ 100) × number

Example: 18% of 250 = (18 ÷ 100) × 250 = 45.

2) Find what percentage one number is of another

Use this when comparing a part to a whole, like “I scored 42 out of 60. What percent is that?”

• Step 1: Divide the part by the whole.
• Step 2: Multiply by 100.
• Formula: (part ÷ whole) × 100

Example: 42 out of 60 = (42 ÷ 60) × 100 = 70%.

3) Find percentage increase or decrease

Use this for salary changes, stock movement, monthly expenses, or traffic growth.

• Step 1: Subtract old value from new value.
• Step 2: Divide by old value.
• Step 3: Multiply by 100.
• Formula: ((new − old) ÷ old) × 100

Example: From 80 to 100 = ((100 − 80) ÷ 80) × 100 = 25% increase.

Using the % button on your calculator

Different calculators treat the percent key a little differently. Many basic calculators allow quick input like:

• To find 20% of 300: type 300 × 20 % and get 60.
• To reduce by 20%: type 300 − 20 % (on some calculators this gives 240).
• For universal reliability: always use the formulas shown above if your calculator behaves differently.

If your calculator output surprises you, switch to the formula method. It works on every scientific calculator, phone calculator, and spreadsheet.

Real-life examples you can copy

Discount shopping

A jacket costs 2,400 and has a 35% discount.

• Discount amount = (35 ÷ 100) × 2,400 = 840
• Final price = 2,400 − 840 = 1,560

Restaurant tip

Your bill is 1,850 and you want to tip 12%.

• Tip = (12 ÷ 100) × 1,850 = 222
• Total payment = 1,850 + 222 = 2,072

Exam score percentage

You got 73 marks out of 90.

• Percentage = (73 ÷ 90) × 100 = 81.11%

Salary hike

Salary increases from 50,000 to 57,500.

• Increase % = ((57,500 − 50,000) ÷ 50,000) × 100 = 15%

Common mistakes to avoid

• Forgetting to divide by 100 when finding a percent of a number.
• Swapping part and whole in percentage score calculations.
• Using new value as denominator in percentage change (use old value).
• Rounding too early, which can slightly distort results.

Quick mental checks

Even with a calculator, quick mental checks prevent errors:

• 10% of any number = move decimal one place left.
• 5% = half of 10%.
• 1% = divide by 100.
• 25% = one-fourth of the number.
• 50% = half of the number.

These shortcuts make it easier to catch accidental keystrokes before you trust a final answer.

FAQ: how to get percentage using calculator

Can I calculate percentage without a % key?

Yes. Just use formulas. For example, 30% of 500 = (30 ÷ 100) × 500.

How do I find the original price after a discount?

If final price is known after discount, divide by the remaining percentage. Example: after 20% discount, remaining is 80%. So original = final ÷ 0.80.

How do I add a percentage to a number?

Multiply by (1 + percentage/100). Example: add 15% to 200 → 200 × 1.15 = 230.

Final takeaway

If you remember just three formulas, you can solve almost every percentage problem confidently. Use the calculator tool above whenever you need fast answers for shopping, exams, taxes, budgeting, or business decisions.