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X is Y Percent of What Calculator

A free online calculator to find the original number when you know a value and its percentage. Used by shoppers finding original prices before discounts, students calculating total scores, and professionals determining base amounts from percentages.

X is Y% of What Number?

Find the original number when you know the percentage and result.

is
%
of what?

For example, to find what number 15 is 30% of, enter 15 in the first box and 30 in the second box. The answer is 50.

Result =
Enter values to see result

To find what number X is Y percent of, divide X by the percentage (Y) and multiply by 100:

Formula: Result = (X / Y) × 100

Or: Result = X ÷ (Y/100)

  • 15 is 30% of what?: (15 / 30) × 100 = 50
  • 20 is 25% of what?: (20 / 25) × 100 = 80
  • 35 is 70% of what?: (35 / 70) × 100 = 50
  • 12 is 40% of what?: (12 / 40) × 100 = 30
  • Find original prices before discount (e.g., $40 is 20% off, what was the original price?)
  • Calculate pre-tax amounts
  • Determine full price from sale price
  • Find original investment amount
  • Calculate total amounts from percentages
  • Determine base salaries from commission percentages
  • Find total target from achieved percentage
  • Calculate full budget from spent percentage
  • Determine total audience from sample percentage

If a shirt costs $45 after a 25% discount, what was the original price?

  • $45 is 75% of what? (100% - 25% = 75%)
  • Result: $60

If you earned 36 points which is 80% of the total, what is the maximum score?

  • 36 is 80% of what?
  • Result: 45 points

If $150 represents 30% of your savings, how much do you have in total?

  • 150 is 30% of what?
  • Result: $500
XY%Result
1050%20
2525%100
3060%50
4590%50
1820%90

When you know that X is Y% of some unknown number, you’re essentially solving:

  • Y% × ? = X
  • Rearranging: ? = X ÷ Y%
  • Or: ? = (X / Y) × 100

How do I find what number X is Y percent of?

Section titled “How do I find what number X is Y percent of?”

Divide X by Y and multiply by 100. For example, if 15 is 30% of what: (15 ÷ 30) × 100 = 50.

What was the original price before a discount?

Section titled “What was the original price before a discount?”

If an item costs 60aftera2560 after a 25% discount, it's 75% of the original price. Enter 60 as X and 75 as Y to get 80 as the original price.

Can I use this for calculating total test scores?

Section titled “Can I use this for calculating total test scores?”

Yes! If you scored 36 points which is 80% of the total, enter 36 as X and 80 as Y to find the maximum score is 45 points.

When Y is less than 100%, the result will be larger than X. This is normal for reverse percentage calculations.

Is this calculator accurate for financial calculations?

Section titled “Is this calculator accurate for financial calculations?”

Yes, the calculator provides precision up to 5 decimal places, making it suitable for financial and business calculations.