About Workmate

I work in electrical and construction sites, and I kept doing the same calculations over and over. Looking up wire sizes from KEC tables. Recreating Excel templates for Korean payroll insurance. Translating American span tables into metric to figure out whether a 2x6 joist could span 4 meters.

So I built this: calculators based on the standards and units used on Korean job sites, in one place. To be honest, similar tools exist on the internet. But most use US units, are clunky on mobile, are buried under ads, or only show the answer without explaining how they got there.

The wire size, voltage drop, breaker sizing, severance pay, annual leave and VAT calculators show the calculation steps. Because you need to attach the rationale to approval documents. Because explaining the formula is faster than handwaving when teaching someone. Because you should be able to verify the result yourself.

What is on this site?

It started as calculators, but there are now four parts — everything you need to work and live in Korea, in one place.

• 81 practical calculators and tools — electrical (KEC), timber, labor, tax, real estate and more. Tax, payroll, wire-size, breaker and voltage-drop calculations show the law or standard behind them
• 20 business forms — quotations, invoices, employment contracts, loan notes, formal notices, risk assessments you can fill in and print
• Korean learning and games — Loopla spaced-repetition study, Hangul typing practice, Korean crossword
• Living in Korea — attraction guides, Korean food, and plain-language summaries of policy changes

Calculators answer the question, the learning tools teach the language, and the guides tell you where to go — the same order anyone arriving in Korea goes through.

Who is this for?

• Korean electrical contractors and exam takers — KEC tables built in
• Wood frame builders — span, material, stairs, foundation in one place
• HR/payroll administrators — Korean 4-major insurance, 2026 rates
• Foreign stock investors filing Korean capital gains tax
• Foreigners living in Korea — visas (F-2-7, D-8), National Pension lump-sum refunds, health insurance, jeonse/wolse, and year-end tax settlement, in English, Chinese and Vietnamese, with situation-by-situation checklists

It started as a tool for Korean tradespeople, but I realized foreigners settling here have nowhere good to find "Korean standards, in English." So I built the visa, tax, housing, and pension tools in English first, and they are now in Chinese and Vietnamese too.

How is the foreigner information verified?

For high-stakes areas like visas, tax, pension, and leases I follow one rule: cite official sources only — the National Pension Service (NPS), National Tax Service (NTS), the health-insurance service (NHIS), HiKorea (immigration), the land ministry (MOLIT), and the relevant statutes. Where sources disagree or the figure is unpublished (e.g. the OASIS score), I don't assert a number — I send you to the agency. Items that vary by nationality or visa status are marked (verify) right in the text.

Rates and laws change. When something is confirmed — like the 2026 rise in the National Pension contribution rate to 9.5% — I update it immediately, and each tool shows a last-reviewed date so you know its basis. Still, always confirm with the agency or a professional before an actual filing or contract — this site is for nailing the first 90% quickly.

One important caveat

Results are for reference only. The structural span calculator applies only some of NDS's seven adjustment factors. The insulation calculator ignores thermal bridging. A structural engineer, electrical safety manager, or tax accountant must review your work before construction or filing. Use this tool to nail down 90%; let the expert nail the remaining 10%.

How is your data handled?

Calculations run in your browser. The values you enter are not sent to a server to be calculated, and are not stored in a database. The JSON↔CSV converter works the same way. Inputs kept so you can pick up where you left off are saved in your browser. Some calculators also put your inputs in the page address (URL). If you share that address, the person you send it to can see the values, and when it is opened, the values may also be recorded in access logs or reach ad services. Visit statistics receive the address with those values removed.

The user information stored in the database is what you choose to sign up for or write — weekly Gov Support email alerts, attraction comments and reactions, and Loopla review reminders — together with the details those features need to work, plus a hash of your IP address (a value that cannot be turned back into the address) to stop repeated sign-ups and spam. Messages sent through the contact form are not stored in a database; they are delivered through the email service Resend to the operator's inbox, and the copies in that inbox are deleted on request. Separately, simply opening the site means the hosting provider processes access logs (IP address, time of access, requested URL); visit statistics (Google Analytics) and ads (Google AdSense and others) may also use cookies to collect browsing activity and interests. What is kept, and for how long, is in the Privacy Policy.

Suggest a tool

If there's a tool you'd like to see here, let me know on the contact & feedback page. When similar requests come in more than once, they get priority.