How to calculate percentage from CGPA

A spread of 13.36 percentage points on one number. That is not a rounding difference — it is the difference between clearing a 75% cut-off and missing it by four points. Which one applies to you is not a matter of preference.

1. Find the formula your own university publishes. Where to look is the next section.
2. Substitute your CGPA into it. Write the substitution down rather than doing it in your head — it is what you will be asked to show if the figure is queried.
3. Truncate the result to two decimals. Do not round up: 79.96% is not 80%.
4. Record which formula you used alongside the number, so the figure can be reproduced later.

CGPA to percentage runs all four and prints the substitution with your own number in it, which is the step most tools skip.

In descending order of authority, and it is worth going down the list rather than stopping at the first plausible answer.

• The examination ordinance or regulations for your programme and admission year. This is the governing document and it is usually a PDF on the university website.
• A conversion circular from the examination section. Universities issue these when students start needing percentages for placements, and they sometimes supersede the ordinance.
• The back of your own grade card. Many universities print the grading key and the conversion there. This is the fastest place to look and the one people check last.
• The examination section directly. A written reply from them is worth more than anything you find on a forum.

A formula a senior gave you, or one from a coaching group, is not a source. The gap between two universities’ formulas is larger than any error you are likely to make in the arithmetic, so getting the formula right matters more than getting the sum right.

It happens, and it is not a dead end. Three routes, in order of preference.

1. Ask the receiving body what they want. Employers and universities deal with this constantly and most have a stated position. Many will accept the transcript with the grading key and do their own conversion.
2. Request a conversion certificate from your examination section. Some issue one on application, and a certificate on university letterhead settles the question permanently.
3. Use the general convention and say so. (CGPA − 0.75) × 10 is the default on this site precisely because it is the least wrong when the issuing university is unknown. State it explicitly next to the figure — “76.50%, converted as (8.40 − 0.75) × 10” — so nobody has to guess how you got there.

It is the formula everyone repeats, and it comes from CBSE, where it was derived from the average marks of high-scoring students in Classes X and XII. It was a school-board device for a school-board scale. Applied to an engineering CGPA it inflates the figure by several points against what your college would certify — 79.80% instead of 76.50% on the general convention, for the same 8.40.

On a job application that gap is a misrepresentation rather than a rounding error, and it is the kind that surfaces at document verification rather than at screening.

If you hold a percentage and need a CGPA, run the same formula backwards. The inverse of (CGPA − 0.75) × 10 is (percentage ÷ 10) + 0.75, so 79.80% returns 8.73. Percentage to CGPA does it and refuses the cases where a formula cannot express the percentage at all — under Mumbai’s rule a ten-point CGPA tops out at 82.00%, so a 90% input has no valid CGPA behind it.