Calculators tools
Everyday calculators for take-home pay, loans and savings, with up-to-date rates.
Korean take-home pay, loan payments, and savings maturity.
Standard weight, healthy range, BMI, obesity ratio and BMR from height, sex and weight. In-browser, free.
Daily calories and protein/fat/carb grams for your goal (lose/maintain/gain). Mifflin-St Jeor, in-browser.
Compute your GPA from course credits and grades on a 4.5 or 4.3 scale. In-browser, no upload.
GCD, LCM and prime factorization of several numbers — big-number accurate, no upload.
Add, subtract, multiply and divide fractions with reduced, mixed and decimal output. No upload.
Mean, median, mode, variance and standard deviation (population and sample) at once. In-browser.
Four percent calculations in one screen: ratio, X% of Y, increase/decrease, and percent change. No upload.
Estimate Korean car tax + education tax from displacement and age. Flat EV rate, in-browser.
Estimate a Korean residential electricity bill with progressive tiers, VAT and fund. Summer tiers included.
New average price, unrealized P/L and shares needed to reach a target average. Not live-quote linked.
Estimate your 2026 mortgage limit from income, price and rate under stress-DSR and LTV rules. In-browser.
Convert jeonse to monthly rent and back at the 2026 legal rate (4.75%). In-browser.
Compute the maximum agent fee by transaction amount from the rate table, with VAT. In-browser.
Housing acquisition tax with education and rural taxes at 2026 rates, including multi-home surcharges. In-browser.
Gross and net rental yield plus the gap (equity) at once, with loan interest. In-browser.
Predict ovulation, fertile window and next period from your last period and cycle length. In-browser.
Estimate due date, current gestational age and trimester from LMP or conception. In-browser.
Convert a dog or cat age to human years — size-based vet model and epigenetic formula. In-browser.
Split any amount into net, VAT and gross at 10%. Net/gross toggle and reverse VAT. In-browser, free.
Korea simplified-taxation VAT payable from business type and annual supply value at 2026 rates.
Korea's 3.3% freelancer and 8.8% other-income withholding — tax, net pay and reverse gross.
Estimate Korean statutory severance from start/end dates and monthly average wage.
Get margin, markup and profit from cost and price, or the price for a target margin.
Convert hourly, monthly and annual wages using Korea 209/174-hour bases.
Korea's 2026 minimum wage (10,320 KRW/h) with daily, weekly, monthly and annual conversions.
Korea weekly holiday pay from hourly wage and weekly hours, with the 15-hour eligibility check.
Korea unused annual-leave pay from monthly ordinary wage and unused days.
Break-even revenue, quantity and contribution margin from fixed cost, price and variable cost.
Korea's four social insurances from monthly salary at 2026 rates — employee and employer shares.
Korea overtime, night and holiday premiums from monthly ordinary wage and hours worked.
Card fee and net settlement from payment amount and your merchant fee rate.
Straight-line and declining-balance depreciation schedules from cost, salvage and life.
Create quotations, statements and invoices with auto VAT and save as PDF. Nothing leaves your browser.
Log BP & pulse in large text with averages and trend; print/share. Reference stages (not a diagnosis), on-device.
A calculator with big buttons and text — VAT 10%, copy result. Nothing sent.
Target age, cycle and cost for Korea's national health and cancer screenings, with an NHIS link.
Adult/senior vaccines split into free (state-funded) and recommended (paid), with a clinic finder.
Enter who paid what and get the fewest transfers to settle up. Share to KakaoTalk. On-device.