Korean numbers, explained

A flat is advertised in pyeong but leased in square meters. Your age is counted three different ways, and which one applies depends on the law. An electricity bill is priced in tiers, so a kilowatt-hour in the highest tier costs more than twice one in the lowest. A baby’s hundredth day is counted from day one, not day zero.

Each calculator shows the result with its formula and assumptions so you can check whether it applies to your bill or paperwork.

Different labels can refer to different measurements. Check what each figure includes before comparing it.

A listing calls a flat 32 pyeong while the register calls the same home 84㎡. The larger number includes your share of the corridors, the lift shaft and the stairwell; the smaller one counts only what sits behind your front door. These are supply area and exclusive area, respectively; the lease uses the exclusive area.

Age works the same way. Korea has counted it three ways, and although the law has defaulted to international age since June 2023, the school year, conscription and the legal drinking age still run on your year of birth rather than your birthday. Which age a form wants depends on what the form is for.

Even counting days splits in two. A deadline of “within 7 days” on a document received on the 21st runs to the 28th, because the civil code does not count the day you received it. A baby’s hundredth day does the opposite: the day of birth is day one, so it falls 99 days later. Each calculator states whether it counts the starting day.

Electricity charges, agent fees and acquisition tax use different rate bands. Check the applicable band before multiplying by a rate.

Household electricity usage is split across three tiers. Crossing a boundary also raises the base charge, so a small increase in usage can raise two parts of the bill. An estate agent’s commission is a ceiling per band rather than a price, and the tenant and landlord each negotiate a separate fee within the applicable cap. Acquisition tax on a home is quoted as 1%, but local education tax and rural development tax may also apply, and an officetel is charged at an entirely different rate.

The calculator results and rate tables show which rates apply to the amount you enter.

Pages link to the rules used in the calculations: the Civil Act for counting periods, the Local Tax Act for property purchases and KEPCO’s tariff for electricity.

Tariffs and holiday rules can change. Pages that depend on them show the date the figure was last checked. The Korean section offers 26 more calculators.