Labour Act, not the government pension file
In the Bangladesh Labour Act, 2006, gratuity is a defined benefit: wages of 30 days for every completed year of service (or a leftover period of more than six months), at the last wage. If service is more than 10 years, the statute uses 45 days per year. “Wages” for this purpose is typically last basic plus dearness allowance — not the full gross with house rent — unless your contract says otherwise.
Resignation of a permanent worker has its own band (commonly 14 days per year after five years, 30 days after ten, or gratuity if that is higher). Retrenchment and many employer terminations use 30 days per year or gratuity, whichever is higher, after one year of continuous service, and notice pay is extra.
Service of more than six leftover months is counted as a full year here. Your appointment letter, a recognised settlement, or a provident-fund scheme can replace or cap these numbers. This calculator is for planning, not a labour-court pleading.
Monthly overtime and leave pay sit on a separate Labour Act page. Government officers drawing NPS 2015 should use govt pension & lump grant instead of this page.