how to take percentage in calculator

How to take percentage in calculator (simple guide)

If you are wondering how to calculate percentage on a calculator, the good news is that it is easy once you know the pattern. You can do most percentage questions with one of these three ideas:

• Find X% of Y (for discounts, tax, tips, commission).
• Find what percent one number is of another (for exam scores, growth rates, ratios).
• Add or subtract a percent from a number (price increase/decrease).

Method 1: Find X% of a number

This is the most common percentage calculation.

Example

Find 20% of 450:

• 20 ÷ 100 = 0.20
• 0.20 × 450 = 90

Answer: 20% of 450 is 90.

Calculator keystrokes (without % key)

Type: 20 ÷ 100 × 450 and press equals.

Method 2: Find what percent X is of Y

Use this when you already have two numbers and want the percentage relationship.

Example

You scored 42 out of 60. What percentage is that?

• 42 ÷ 60 = 0.70
• 0.70 × 100 = 70

Answer: 42 is 70% of 60.

Method 3: Add or subtract percentage

This is useful for salary hikes, discount shopping, and inflation calculations.

Increase by percentage

Example: Increase 1,000 by 15%:

• 1 + 15/100 = 1.15
• 1,000 × 1.15 = 1,150

Decrease by percentage

Example: Decrease 1,000 by 15%:

• 1 - 15/100 = 0.85
• 1,000 × 0.85 = 850

How to use the % button on a calculator

Different calculators treat the % button slightly differently, but for basic shopping math it usually works like this:

• For 10% of 500, type 500 × 10 %.
• For 10% discount on 500, type 500 - 10 % (on many calculators).
• For 10% increase on 500, type 500 + 10 % (on many calculators).

If your calculator gives confusing results, use the formula methods above—they work on every calculator and even in your head with practice.

Common real-life percentage problems

1) Discount

A shirt is $80 with 25% off.

• Discount = 25% of 80 = 20
• Final price = 80 - 20 = 60

2) Tax

Item price is $250, tax is 8%.

• Tax = 8% of 250 = 20
• Total = 250 + 20 = 270

3) Tip

Restaurant bill is $64, tip is 15%.

• Tip = 15% of 64 = 9.60
• Total bill = 73.60

Common mistakes to avoid

• Forgetting to divide by 100. Percentage means “per hundred.”
• Mixing up part and whole. In (part ÷ whole) × 100, order matters.
• Subtracting percent directly from number. Don’t do 200 - 10 for 10% off. Use 200 - (10% of 200).
• Rounding too early. Keep at least 2–4 decimals until the end for better accuracy.

Quick percentage cheat sheet

• 10% of a number = move decimal one place left.
• 5% = half of 10%.
• 1% = divide by 100.
• 25% = one-fourth.
• 50% = half.
• 75% = three-fourths.

Final takeaway

To take percentage in a calculator, remember the core formulas and you can solve almost anything. Use the calculator tool above whenever you need a fast answer for percentage increase, decrease, discount, tax, marks, or business calculations.