Utileno
EN한국어
LOCAL TOOL · MATH

Percentage Calculator

Answer the three most common percentage questions instantly — everything runs in your browser.

INPUT

What is X% of Y?

What is % of ?

Calculated locally in your browser.

–

How to use

  1. Pick the card that matches your question — each card solves one type of percentage problem.
  2. Type your numbers into the blanks. The result appears instantly as you type; there is no submit button.
  3. Use Copy to copy a result, or change the numbers to recalculate.

Examples

Tip: what is 15% of $64?

Type 15 and 64 into “What is X% of Y?”. The result is 9.6, so a 15% tip on a $64 bill is $9.60.

Quiz score: 42 out of 60 as a percent

Type 42 and 60 into “X is what percent of Y?”. 42 ÷ 60 × 100 = 70, so the score is 70%.

Price change: from $80 to $92

Type 80 and 92 into the percentage change card. The difference is +12, which is a 15% increase.

Percentage Increase / DecreaseEnter the original and the new value — get the percent change, its direction, and the difference instantly.Discount CalculatorEnter a price and a % off to see the sale price and exactly how much you save.Ratio CalculatorSimplify a ratio to its lowest terms and scale it to any size — both directions.

FAQ

How do I calculate X percent of a number?

Divide the percentage by 100 and multiply by the number: X% of Y = (X ÷ 100) × Y. For example, 25% of 80 = 0.25 × 80 = 20.

How do I work out what percent one number is of another?

Divide the part by the whole and multiply by 100: (part ÷ whole) × 100. For example, 30 out of 120 is (30 ÷ 120) × 100 = 25%.

How is percentage change calculated?

Percentage change = (new − original) ÷ |original| × 100. Going from 40 to 50 is a 25% increase, while going from 50 to 40 is a 20% decrease — the baseline differs, which is why the two answers are not the same.

Why can’t I calculate a percentage change starting from zero?

Percentage change compares the difference against the original value. When the original value is 0 there is no baseline to compare against (division by zero), so the calculator reports it as undefined instead of showing a misleading number.

Are the numbers I type uploaded anywhere?

No. The calculator runs entirely in your browser — your numbers are processed locally and are not sent to our servers.

How many decimal places are shown?

Results show up to 6 decimal places with trailing zeros removed. The exact result is rounded once at the end, so there is no hidden intermediate rounding.