Many forms abroad ask for a percentage, but Bangladeshi results are given as GPA. Here is how to handle it.
SSC and HSC
Both use a 5-point GPA scale, where 5.00 is the maximum. A+ (GPA 5) is generally awarded for marks of 80 and above. The board result does not map to one official percentage, so for applications use the marks on your transcript where a percentage is asked for.
University CGPA
Many universities use a 4.00 scale, but some use different scales, so the same number can mean different things. Check your own transcript for the grading scale.
No universal formula
A simple estimate some institutions accept is CGPA divided by the maximum scale, times 100. For example 3.50 on a 4.00 scale gives 87.5%. However, many universities and employers have their own rules, so ask the receiving institution which one they want, and avoid presenting an estimate as official.
Calculate your GPA
Use the GPA Calculator to work out a cumulative GPA across courses, or to see what you need to reach a target.