The short answer
Use your institution's own formula. The CGPA to Percentage Calculator carries each verified formula with its source — pick your system, enter your CGPA, and it converts (and inverts) with that formula only.
Why one CGPA gives many percentages
A CGPA of 8.0 is 76% under CBSE, 80% under Anna, 72.5% under VTU, and 70.4% under SPPU Engineering. Same CGPA, four different percentages. The formula is what differs. Any site that converts with a single “standard” formula is using somebody's formula — probably not yours.
Verified formulas
| System | Formula | Source |
|---|---|---|
| CBSE | Percentage = CGPA × 9.5 | CBSE Circular No. 24 / 28-05-2010 (cited; strong secondary) |
| VTU | Percentage = (CGPA − 0.75) × 10 | VTU Regulations 18OBP 12.1 (via mirror) |
| SPPU Engineering, 2015 pattern | Percentage = CGPA × 8.80 | SPPU Board of Examinations letter 27/07/2018 (via mirror) |
| Anna University | Percentage = CGPA × 10 | Anna University Academic Regulations (primary) |
| GTU | Percentage = (CGPA − 0.5) × 10 | GTU Notification 1/2012 (quoted; secondary) |
Notes on each formula
- CBSE ×9.5: derived from five years of data — the top band averaged ~95 marks, 95 ÷ 10 = 9.5. Consequence: CGPA 10 → 95%, not 100%. A percentage above 95 has no CBSE CGPA equivalent.
- VTU (CGPA−0.75)×10: the same formula is sometimes attributed to UGC guidance, but the UGC Guidelines PDF itself contains no conversion. Do not attribute it to the UGC Guidelines.
- SPPU ×8.80: engineering, 2015 pattern, per the 2018 circular. The 2019 pattern was not verified from a primary circular.
- Anna ×10: stated identically in Anna's MBA 2019 and UG 2019 amended regulations. This settles Anna against forum claims of (CGPA−0.5)×10.
- GTU (CGPA−0.5)×10: per Notification 1/2012, effective Winter 2011.
Mumbai University — contested, not settled
Two CBCS claims circulate: 7.1 × CGPA + 11 and 7.25 × CGPA + 11. At CGPA 8.0 they differ by 1.2 percentage points (67.8 vs 69.0). Engineering has a separate piecewise formula (CGPI < 7: 7.1 × CGPI + 12; CGPI ≥ 7: 7.4 × CGPI + 12). None is verified from MU's own circular. Verify against Circular 1883 of 2017 before using any MU formula — and treat any site that asserts one MU formula as settled with suspicion.
Percentage → CGPA
Invert your institution's own forward formula: CBSE: CGPA = percentage ÷ 9.5. Anna: CGPA = percentage ÷ 10. VTU: CGPA = (percentage ÷ 10) + 0.75. GTU: CGPA = (percentage ÷ 10) + 0.5. SPPU: CGPA = percentage ÷ 8.80. Inversion is valid only under that institution's formula, and rounding to two decimals loses precision.
CGPA → US 4.0 GPA
There is no official conversion. The common linear estimate is (percentage ÷ 100) × 4. Credential evaluators evaluate course by course. Never present the linear estimate as an official conversion.
What not to use
- “UGC ×10” / “AICTE ×10” — no such prescription was found. The UGC Guidelines define SGPA/CGPA but prescribe no conversion.
- Another university's formula — the table above shows why.
- Plain-average CGPA — compute CGPA the credit-weighted way first (CGPA Calculator), then convert.
- Forum formulas — SPPU (CGPA−0.5)×10, Anna (CGPA−0.5)×10, and SPPU sliding-scale tables are contradicted by the primary documents.
Tools: CGPA to Percentage Calculator, CGPA Calculator, SGPA Calculator. Guides: How to Calculate CGPA, How to Calculate SGPA.