How GPA Is Calculated at Thai Universities
Thai universities use a credit-weighted GPA formula identical in structure to the US system but applied to a different grade scale. The Thai scale uses 8 grade levels with half-step grade points, and GPA is calculated by multiplying each course's grade points by its credit hours, summing all those products (called quality points), and dividing by total credit hours.
- Grade Points = numeric value from the Thai 4.0 scale: A = 4.0, B+ = 3.5, B = 3.0, C+ = 2.5, C = 2.0, D+ = 1.5, D = 1.0, F = 0.0
- Credit Hours = the credit value assigned to each course (typically 3 for lecture courses, 1 for laboratory or seminar components)
- Sum = totalled across all courses in the calculation period (one semester for semester GPA; all semesters for cumulative GPA)
Credit weighting has an outsized effect on GPA when courses vary widely in credit value. A 3-credit core course contributes three times as much to the GPA as a 1-credit lab. Students at Thai universities who are targeting First Class Honours (GPA 3.50 or above) should focus on high-credit required courses. Use the calculator above to model the exact GPA impact of each course and identify which subjects carry the most weight.
Thailand University Grading Scale
The Thai grading system uses 8 grade levels with grade point values at whole and half intervals between 0.0 and 4.0. The half-step grades (B+, C+, and D+) occupy the midpoints between adjacent whole-number grades. This structure is consistent across virtually all Thai public universities governed by the Office of the Higher Education Commission (OHEC).
Honor Classifications in Thailand
Thai universities award degree classifications based on cumulative GPA. The thresholds below are standard across OHEC-governed institutions, though some faculties (engineering, medicine) may impose additional conditions such as no failed courses and completion within the standard program duration.
- First Class Honours (GPA 3.50 or above): Called Eiatyom (เกียรตินิยมอันดับหนึ่ง) in Thai, this classification is the highest degree honor. A GPA of 3.50 is achieved by maintaining an average of B+ across all courses. Recipients are typically eligible for government scholarships, OHEC academic development grants, and competitive civil service entry programs. Most First Class graduates from leading Thai universities are also competitive for postgraduate programs at international institutions.
- Second Class Honours (GPA 3.00 to 3.49): Called Eiatyom An-dab Song (เกียรตินิยมอันดับสอง) in Thai. This classification maps to a B average and is the minimum for most Thai government scholarship programs requiring an honors degree. It is also the standard minimum for most Thai postgraduate programs and for positions in government-linked organizations.
- Pass (GPA 2.00 to 2.99): Satisfies the minimum graduation requirement at most Thai universities. A Pass degree meets minimum eligibility for Thai civil service positions and most private-sector entry-level roles, though competition for professional positions often effectively requires Second Class Honours or above.
- Academic probation (GPA below 2.00): Students whose cumulative GPA falls below 2.00 are typically placed on academic probation. Those who remain below 2.00 for two consecutive semesters risk dismissal. Some universities allow probationary students one additional semester to raise their GPA above the minimum threshold.
Thai Universities and Their GPA Practices
All eight universities in the directory below use the standard Thai 4.0 scale with A/B+/B/C+/C/D+/D/F grades. The calculator on this page handles all of them without any mode change needed. Credit hour structures and program lengths vary, but the grade point values are uniform across Thai public universities.
| University | Abbrev. | City | GPA Scale |
|---|---|---|---|
| Chulalongkorn University | CU | Bangkok | 4.0 (Thai standard) |
| Mahidol University | MU | Nakhon Pathom | 4.0 (Thai standard) |
| Kasetsart University | KU | Bangkok | 4.0 (Thai standard) |
| King Mongkut's Univ. of Tech. Thonburi | KMUTT | Bangkok | 4.0 (Thai standard) |
| Asian Institute of Technology | AIT | Pathum Thani | 4.0 (Thai standard) |
| Chiang Mai University | CMU | Chiang Mai | 4.0 (Thai standard) |
| Thammasat University | TU | Bangkok | 4.0 (Thai standard) |
| Prince of Songkla University | PSU | Songkhla | 4.0 (Thai standard) |
Chulalongkorn University (CU) and Mahidol University (MU) are the two most internationally recognized Thai institutions and are consistently ranked first and second in Thai university rankings. Both use the standard Thai grading scale described above. The Asian Institute of Technology (AIT) is a postgraduate institution that attracts students from across Southeast Asia; its programs are taught in English and the GPA scale is consistent with the Thai national standard, making it directly comparable with other Thai university transcripts.
Convert Thailand GPA to US 4.0 Scale
Because Thai universities and US universities both use a 4.0 maximum GPA scale, numerical values transfer directly for most graduate school application purposes. A Thai GPA of 3.50 is 3.50 on the US 4.0 scale, and the calculator above shows the US 4.0 equivalent in the results panel as a direct read-through.
The practical difference lies in what the GPA represents at the percentage level. Thai universities typically set the A grade at 80 percent and above, while US universities commonly set A at 90 to 93 percent. This means a Thai student who consistently scores 82 percent earns an A (4.0 grade points) in Thailand, while the same 82 percent at a US university would typically earn a B or B+ (3.0 to 3.3 grade points). Consequently, a given GPA at a Thai university represents a higher absolute percentage performance than the same number at most US universities.
| Thai Grade | Thai Points | Thai % Range | Nearest US Equivalent | US Points |
|---|---|---|---|---|
| A | 4.0 | 80 to 100 | A / A- | 4.0 / 3.7 |
| B+ | 3.5 | 75 to 79 | A- / B+ | 3.7 / 3.3 |
| B | 3.0 | 70 to 74 | B | 3.0 |
| C+ | 2.5 | 65 to 69 | B- | 2.7 |
| C | 2.0 | 60 to 64 | C+ | 2.3 |
| D+ | 1.5 | 55 to 59 | C / C- | 2.0 / 1.7 |
| D | 1.0 | 50 to 54 | D | 1.0 |
| F | 0.0 | Below 50 | F | 0.0 |
For formal graduate school applications to US institutions, World Education Services (WES) is the most widely recognized Thai credential evaluator. WES uses the official transcript and grade key from the Thai university rather than a generic conversion table, and their evaluations are accepted at most US and Canadian universities. For preliminary reviews, most admissions offices accept the Thai GPA directly on the 4.0 scale without a formal evaluation.
For UK postgraduate applications, Thai First Class Honours (GPA 3.50 or above) is generally treated as equivalent to a UK First Class degree, meeting the standard admission requirement for most taught Master's programs at UK universities. Thai Second Class Honours (GPA 3.00 to 3.49) typically maps to a UK 2:1, which is the standard minimum for most UK postgraduate programs.
Honor Thresholds by University
The honor classification thresholds above are common across Thai public universities, but several major institutions have their own published regulations that differ from the general standard. Chulalongkorn University sets a higher bar for First Class Honours than most other institutions. Always check your faculty's academic regulations before planning your GPA target.
| University | First Class Honours | Second Class Honours | Source |
|---|---|---|---|
| Chulalongkorn University (CU) | GPA 3.60 or above | GPA 3.25 to 3.59 | CU Regulations on Awarding Honours Degrees (B.E. 2552) |
| Mahidol University International College (MUIC) | GPA 3.50 or above | GPA 3.25 to 3.49 | MUIC Academic Resources, Honors and Probation |
| Most Thai public universities (OHEC standard) | GPA 3.50 or above | GPA 3.00 to 3.49 | Office of the Higher Education Commission general policy |
| Kasetsart University (KU) | GPA 3.50 or above | GPA 3.00 to 3.49 | KU Academic Regulations |
| Thammasat University (TU) | GPA 3.50 or above | GPA 3.00 to 3.49 | TU Academic Regulations |
Chulalongkorn's 3.60 First Class threshold is notably higher than the standard 3.50 at other institutions. A student targeting First Class Honours at CU needs a sustained A average, while the same performance at Thammasat or Kasetsart would qualify comfortably. Both CU and MUIC also impose additional conditions beyond GPA: no F or U grades on record, and completion of the degree within the standard program duration. Check the exact requirements in your faculty's academic secretariat before making graduation plans.
TCAS Admission and GPAX
Thai high school students applying to university through the TCAS (Thai University Central Admission System) need to understand a different GPA metric: GPAX (Grade Point Average Cumulative). GPAX is the cumulative average of all six semester GPAs from Grades 10 through 12 (Matthayom 4 through 6 in the Thai system). Each semester is weighted equally in the simple average.
- Semester GPA = the GPA for each semester of Grades 10, 11, and 12 (3 school years, 2 semesters each)
- All six semesters are weighted equally in the simple average
- GPAX is reported on a 4.0 scale using the same Thai grade point values: A = 4.0, B+ = 3.5, B = 3.0, C+ = 2.5, C = 2.0, D+ = 1.5, D = 1.0, F = 0.0
GPAX carries significant weight in TCAS Round 1 (Portfolio) and Round 2 (Quota), where many programs set minimum GPAX requirements. Engineering programs at top-tier institutions frequently require GPAX of 2.75 or above; medical and dental programs typically require 3.00 or above. The GPAX metric is separate from the university GPA calculated once enrolled. High school GPAX ends at university entrance; the university GPA calculation starts fresh with the first semester of the undergraduate program.
Sources and Verification
Grade point values and percentage thresholds on this page are cross-referenced against published grading policies at Chulalongkorn University (including the CU Regulations on Awarding Honours Degrees, B.E. 2552) and Mahidol University International College. General OHEC policy guidance is drawn from the Office of the Higher Education Commission (OHEC / MUA). International equivalence information is sourced from World Education Services (WES). Individual university honor classification thresholds may change with academic year updates. Verify current requirements with your faculty registrar before making enrollment or graduation planning decisions.
For SE Asian GPA comparisons, see also the Indonesia GPA calculator (IPK on the 4.0 scale) and the Singapore GPA calculator. For conversion tools, the GPA converter handles Thai-to-US and other international scale conversions. The standard GPA calculator covers the US 4.0 scale.
Last verified: May 2026