Percentage Calculator
The four percentage questions people ask most, on one screen: what is Y% of X, X is what percent of Y, what's the percent increase or decrease from X to Y, and what's X after adding or taking off Y%. Just enter the numbers.
Enter a date of birth to see the age.
Age
- Next birthday in
- Days lived
- Korean year age
- Traditional Korean age
Since June 2023, Korean law, contracts and official documents use international age. Year age is only used where a law says so, such as military service and youth protection.
People born on February 29 are counted one year older on March 1 in non-leap years.
What is Y% of X?
Answer
X is what percent of Y?
Answer
Percent change from X to Y?
Answer
X increased or decreased by Y%?
Answer
Korean VAT (10%)
VAT is 10% of the supply value. Working back from a total, VAT is total × 10/110.
- Supply value
- —
- VAT
- —
- Total
- —
Computing the tax per item and rounding each before adding can differ slightly from the tax computed once on the total.
Days between two dates
- In weeks
- In months
Pick two dates to see how many days apart they are.
Add or subtract days (D-day)
Enter height and weight to see your BMI.
- Total interest
- Total paid
| No. | Payment | Principal | Interest | Balance |
|---|
About this tool
How to use it
- 1 Find the question you need — there are four, stacked top to bottom.
- 2 Enter X and Y and the answer appears.
- 3 For a sale price or a price after a raise, use the last question and pick Increase or Decrease.
Good to know
- Loan interest uses the annual rate divided by 12. Lenders that charge daily interest can differ by a few cents per payment
- Prepayment fees, grace periods and variable rates are not supported
- BMI is not a reliable measure for children and teens, during pregnancy, or for very muscular people
Frequently asked questions
How do I work out a 30% discount?
In the last question, enter the original price as X and 30 as Y, then choose Decrease.
Percent change vs. percentage points?
Going from 10% to 15% is a 5 percentage-point rise but a 50% increase. The third question gives the percent change.
Can I type thousands separators?
Yes, 1,000 is read as a number.
Tools that pair well with this
-
Bill splitter
Log what each person spent per item and get the exact transfers that settle it up.
-
Pomodoro timer
25 minutes of focus, 5 of rest, alternating automatically. Today's count stays on this device.
-
Mental math drill
Numbers flash on screen and vanish. You hold them in your head, not your eyes, and add or multiply.