I started RozKaTool as a small set of free tools for Pakistan — a bijli bill calculator, a salary tax calculator, a few PDF tools. It now has 61 tools, and the most interesting thing that happened along the way is that people from other countries started using it. So I kept going across Asia. This week I added three more calculators, each one built around a law I had to read properly before writing a single line of code.
1. Philippines: 13th month pay
Every rank-and-file private-sector employee in the Philippines who worked at least one month in the year is entitled to 13th month pay under Presidential Decree No. 851. The formula looks simple — total basic salary earned during the year divided by 12 — but the divisor is always 12, never the number of months you worked. That is what makes it pro-rated automatically: six months of service earns half a month's basic pay.
The traps are in the details. Basic salary excludes overtime, allowances, holiday premium and COLA. Unpaid absences reduce the amount; paid leave does not. And the tax-free part is shared: your 13th month pay plus your other bonuses is exempt only up to ₱90,000 combined in a year under the TRAIN Law. The calculator shows the tax-free part and the taxable excess separately, because that is the number people actually argue about with payroll.
https://asaantools.pages.dev/philippines-13th-month-pay-calculator/
2. Sri Lanka: gratuity
Sri Lanka's Payment of Gratuity Act No. 12 of 1983 pays half a month's salary for each completed year of service — but only after 5 years of continuous service, and only if the employer had 15 or more workers. Before 5 years, nothing is payable (except on death or ill-health retirement), which surprises a lot of people who resign at year four.
Monthly-paid and daily-paid workers use different formulas: last month's wage divided by 2, times years of service — or 14 times the daily wage, times years. The Act pays only on completed years, so the calculator shows the strict statutory figure by default and lets you add a pro-rata part year if your employer follows that practice. Gratuity must be paid within 30 days of termination.
https://asaantools.pages.dev/sri-lanka-gratuity-calculator/
3. Nepal: income tax for FY 2083/84
Nepal changed its salary tax from FY 2083/84 (mid-July 2026): one unified slab for everyone — 1% up to NPR 10 lakh, then 10%, 20%, 27% and 29%. The old separate single and married scales are gone, the exempt band doubled from NPR 5 lakh, and the top rate fell from 39% to 29%. Most salaried workers pay less than last year.
The 1% first band is a social security tax, waived for SSF contributors — a detail that is easy to get wrong and worth real money. The calculator covers both FY 2083/84 and the previous FY 2082/83, applies the deduction cap (lower of NPR 5,00,000 or one-third of income), and shows monthly TDS so you can check your payslip line by line.
https://asaantools.pages.dev/nepal-income-tax-calculator/
What building these taught me
First, a calculator is only as good as the law behind it. Every one of these pages links the rule it implements — PD 851, the 1983 Gratuity Act, the Finance Acts — and carries a disclaimer that it is an estimate, not legal or tax advice. If I cannot name the source of a rate, the tool does not ship.
Second, the edge cases are the product. The happy path (full year, same salary, no absences) is the easy 10% of the work. The value is in the pro-rata months, the part-year service, the SSF waiver — the situations real people actually have.
Third, everything still runs in the browser. No sign-up, no upload, no server: your salary figures never leave your device. That is the whole point of RozKaTool, and it matters more for a payslip calculator than for a PDF merger.
All 61 tools are free at https://asaantools.pages.dev/ — PDF, image and everyday calculators, including the Pakistan tools it started with. If there is a payslip rule from your country that you check every month, tell me in the comments — that is usually the next tool I build.
