Calculator (Basic, Scientific, VAT, Discount, Percent, Split Bill, Loan)
A calculator from basic arithmetic to trigonometry and logs, plus VAT, discount, percent, bill-splitting, loan-interest and amount-in-words calculators, and unit/date expressions such as “5km + 300m to mi” or “today + 100 days”. Everything is computed on this page and history stays in this browser.
History
No history yet. Type an expression and press = to add one.
The latest 100 entries are kept in this browser only. Nothing is sent to a server, and clearing browser data removes them.
Monthly schedule
| No. | Payment | Principal | Interest | Balance |
|---|
Enter a number to get Korean (hanja and hangul formal), spoken Korean and English; enter a Korean amount to get the number. Formal numerals never drop 일(壹)/십(拾), so digits cannot be slipped in. Under 20 digits.
Units: "number unit (+/− number unit) to unit" — same kinds are added or subtracted, then converted. Dates: "date ± duration" or "date − date" (durations in days, weeks, months, years; today, tomorrow and yesterday work as dates). It uses the same rules as the Unit Converter and the Date Calculator.
See every unit in the Unit Converter · More in the Date Calculator
A simple calculation. Savings payments are assumed at the start of each month, and interest and tax are rounded down to whole won. Bank bonus rates, day-count conventions, early withdrawal and tax-preference eligibility are not modeled, so real results can differ by tens to hundreds of won.
This is not medical advice. Results are rough estimates from statistical formulas and vary widely with muscle mass, body fat, medical conditions and pregnancy. Nothing you enter is stored or sent.
BMI classes follow the Korean Society for the Study of Obesity (Asia-Pacific) cut-offs, which are lower than Western ones (25 overweight, 30 obese). BMR uses Mifflin–St Jeor with the revised Harris–Benedict shown alongside. These are adult standards, so no BMI class is given under 19.
Enter what each person paid to get every share and who should send whom how much, using the fewest transfers. Names and amounts never leave this browser.
Format: payer amount [note] [@person,person]. Without @, everyone shares. Names must not contain spaces.
Leftover units that do not divide evenly are paid by the person who paid. Rounding applies to each net balance and the difference is absorbed by the person with the largest balance. With more than 16 people the transfer count may not be the minimum (at most people − 1).
Simple arithmetic, not investment advice. Nothing you enter is saved or sent.
Average price of split purchases
Buy more · target average
Sale profit and loss
Tax rates change every year and commissions differ by broker, so edit the fields. Overseas capital gains tax and dividends are not covered. Decimal prices (e.g. dollars) are fine.
Enter distance, fuel economy and fuel price to get the fuel cost, then add tolls and parking for a total and a per-person share. Fuel prices change weekly, so enter today's price.
Pump price (KRW/L) or charging price (KRW/kWh).
The per-person amount is rounded up. Real fuel economy varies with road, speed and load, so this is an estimate. Nothing you enter is saved or sent.
Convert between cost, price and margin, and see what you really keep after card, delivery-app or marketplace fees and VAT. Nothing you enter leaves this browser.
Purchase price or materials. Enter the amount without VAT.
Adding 30% to cost is a 30% markup but only a 23.1% margin. Mixing the two is the most common pricing mistake.
Card, delivery-app and marketplace fees differ by company and contract. Enter the rate from your statement. It is applied to what the customer pays.
Input-VAT deductions and simplified-taxpayer rules are not modeled. This is a rough guide; check real tax questions with an accountant.
Get the volumetric weight from length × width × height, compare it with the real weight and see the billable weight. Light, bulky boxes are charged by volume.
Format: length width height [weight] [xCount]. Weight and count are optional.
Every carrier has its own limits. Enter the figure from the carrier you use and the box is checked against it. No carrier rates are calculated.
5,000 is the most common divisor for air freight; some carriers use 6,000 or 8,000. Check your carrier’s terms for the real rule.
List courses, credits and grades to get your GPA, convert it to another scale and see the average you need in the remaining credits to hit a target. Grades are never sent or stored.
Format: name credits grade. Grades: A+ A0 B+ … F; pass/fail P·NP (S·U). Pass/fail courses stay out of the GPA, and P counts toward earned credits only.
Toward a target GPA
Grade tables and retake rules differ by school. This uses a common table; for official conversion (grad school, scholarships) use your school’s transcript.
Exact fraction arithmetic with the working, GCD and LCM of several numbers, and prime factorization. Big numbers stay correct to the last digit.
Accepts 3/4, 1 2/3 (mixed), -5/6, 0.75 and repeating decimals like 0.(3).
Positive whole numbers only.
From 2 up to 10^15. Larger numbers are not factored.
Annual car tax (private passenger car, Korea)
Acquisition tax (new car)
Reductions for light and electric cars change often, so enter the amount yourself. Check Wetax or your dealer's quote.
Car loan (equal installments)
For reference only. Commercial vehicles, vans and trucks use other rates, and the bill from your local government may differ by a few dozen won. Bonds, plates and delivery fees vary by region and dealer and are not included. Nothing you enter goes to a server.
List your monthly and yearly subscriptions to see the total per month and year, which costs the most, what is billed in the next 30 days, and get billing days as a calendar file. The list is saved only in this browser.
Name, amount, cycle (month / year / week), billing day (month: 1–31 · year: 3-20 · week: mon–sun). Cycle and day are optional. Use one currency only.
Billed in the next 30 days
Billing on the 29th–31st falls on the last day in shorter months. Only subscriptions with a billing day go into the calendar.
Turn prices of differently sized products into a price per 100 g (or 100 ml, or per piece) to see which is cheaper. Handles 1+1 deals and multipacks.
Format: name price size [deal or xCount]. Name without spaces; size like 500g · 1.5L · 6x350ml · 3pcs. Deals: 1+1 · 2+1.
g/kg (weight), ml/L (volume) and pieces are compared only within their own kind. Weight and volume cannot be converted, so they are ranked separately.
Write one function per line and see them plotted. Drag to pan, scroll to zoom, and find roots and intersections. Your formulas never leave the browser.
Variable x. + − * / ^ ( ), implicit multiplication (2x), sin cos tan asin acos atan sinh cosh tanh ln log log2 exp sqrt cbrt abs floor ceil round sign, constants pi e.
Drag to pan, mouse wheel to zoom; with the keyboard use the arrow keys and + −.
Roots and intersections are approximations found inside the visible x range. Fractional powers of negative numbers, such as (-8)^(1/3), are not calculated.
Exchange rates change by the minute, so this tool does not look them up for you. Type the rate you see in your bank app or a rates site and it converts, then estimates what you actually get after the currency-exchange spread and any preferential discount.
The margin a bank adds to the base rate. Cash is usually 1.5–2%, transfers less.
90 means 90% of the spread is waived.
Rates are values you type yourself (kept only in this browser, never sent to a server). For yen, dong and rupiah enter the rate per 100 units, as bank apps show it. The amount you receive is rounded down at the currency’s decimals. Bank-specific fees, wire fees and taxes are not included.
A rough estimate of KOREA Electric Power (KEPCO) residential low-voltage charges. Welfare, large-family and newborn discounts, the essential-usage credit, solar and zero-energy reductions and bill rounding are not included, so your actual bill may differ. City gas is left out because rates differ by region and supplier. In July–August the progressive tiers widen (300 / 450 kWh), and usage above 1,000 kWh in July–August and December–February is charged at the super-user rate.
Expressions and amounts you enter are never sent to a server. Double-check anything important (tax, settlements).
How it calculates
- Arithmetic is exact decimal math: 0.1+0.2 is 0.3 (no floating-point error). Division is computed to 20 decimals and shown to 15 digits.
- Multiplication and division come before addition and subtraction; powers (^) associate right to left (2^3^2 = 512) and -2^2 is -4. You may omit the multiplication sign: 2(3+4), 2π.
- % works like a pocket calculator: 200+10% is 220 (adds 10% of 200) and 50×10% is 5.
- Trig functions use degrees (DEG) by default; switch to RAD for radians. Tiny errors such as sin(180°) are cleaned up to 0.
- Factorials work up to 170!. An unclosed parenthesis is closed automatically when you press =.
- VAT defaults to 10%. When working back from a total, the net amount is rounded first and VAT = total − net, so the two always add up to the total.
- Amounts are computed as whole currency units, so there is no drift. Fractions are handled with the rounding you choose.
FAQ
How do I get the net amount and VAT?
VAT is net × 10% and total is net + VAT. If you only know the total, net = total ÷ 1.1. Pick the direction on the VAT tab.
Why is a stacked discount not the sum of the discounts?
A 20% discount followed by 10% is 28%, not 30%, because the second applies to the already reduced price. The "Stacked discounts" mode shows the combined rate.
Where is my history stored?
Only in this browser (localStorage); nothing is sent to a server. You can turn saving off or clear it.
How to use this tool
Everyday calculations in one place. From basic and scientific calculators to VAT, discounts, percentages, bill splitting, loan interest, savings, health (BMI and basal metabolism), exchange, electricity bill, settlement, stocks, trip budget, margin, parcel, GPA, math, unit price, graphs, cars and subscriptions — pick a tab.
Frequently asked questions
How do I calculate 10% VAT?
In the VAT tab enter the net or total amount and the tax and remainder are shown.
Which loan repayment methods can I compare?
The loan tab compares equal payment, equal principal, and bullet repayment with monthly payments and total interest.
Can it split a bill?
Yes. Enter the total and head count in the split tab, or use the settle tab to divide group expenses per person.
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