Convert Thai Grades to US GPA

Scale: Thai universities use a 4.0 GPA scale with letter grades tied to percentage scores, administered under Ministry of Higher Education guidelines.  |  Range: 0–100 percentage, 4.0 GPA
US GPA Equivalent
4.00
Excellent
US Letter Grade
Thailand Grade
A
Score Range
80–100
Classification
Excellent

How Thai University Grading Works

Thailand's higher education system is governed by the Ministry of Higher Education, Science, Research and Innovation (MHESI). Public and private universities across the country follow a standardised letter-grade system mapped to a 4.0 GPA scale. The GPA is called เกรดเฉลี่ยสะสม (Cumulative GPA) or simply เกรดเฉลี่ย.

Credits are measured in หน่วยกิต (credit hours), similar to the US system. A typical undergraduate programme requires 120–130 credit hours over four years. Each semester's GPA is calculated separately, and the overall cumulative GPA is used for graduation and applications.

The standard grade scale runs: A (80–100, 4.0) — excellent academic performance; B+ (75–79, 3.5) — very good; B (70–74, 3.0) — good; C+ (65–69, 2.5) — fairly good; C (60–64, 2.0) — fair; D+ (55–59, 1.5) — poor; D (50–54, 1.0) — very poor but passing; F (below 50, 0.0) — failing. Some institutions also use grade codes like S (Satisfactory), U (Unsatisfactory), and I (Incomplete) for non-credit or pass/fail courses.

Honours classifications in Thailand: First Class Honours requires a cumulative GPA of 3.5+ with no F grades and completing the programme within the standard duration. Second Class Honours (First Division) typically requires 3.25–3.49, and Second Class Honours (Second Division) covers 3.00–3.24.

Thailand to US GPA Conversion Table

Grade Score Thai GPA US GPA Description
A 80–100 4.00 4.00 Excellent
B+ 75–79 3.50 3.50 Very Good
B 70–74 3.00 3.00 Good
C+ 65–69 2.50 2.50 Fairly Good
C 60–64 2.00 2.00 Fair
D+ 55–59 1.50 1.50 Poor
D 50–54 1.00 1.00 Very Poor
F < 50 0.00 0.00 Fail

Conversion Example

Student: Nattaya studies Computer Science at Chulalongkorn University (CU) in Bangkok and is applying to US master's programmes in data science.

Her final semester grades: Algorithms A (3 credits), Database B+ (3 credits), Machine Learning A (3 credits), Statistics B (3 credits), Thesis Research B+ (6 credits).

GPA = (3×4.0 + 3×3.5 + 3×4.0 + 3×3.0 + 6×3.5) / (3+3+3+3+6) = (12 + 10.5 + 12 + 9 + 21) / 18 = 64.5 / 18 = 3.58 GPA

US equivalent: 3.58 / 4.0 — a strong profile qualifying for First Class Honours and competitive for top US MS programmes.

Frequently Asked Questions

A Thai grade of A (80–100%, 4.0 GPA) is the equivalent of a US A grade. Both represent excellent academic performance at the top of the grading scale.
Multiply each course's grade points by its credit hours (หน่วยกิต), sum all products, then divide by the total number of credit hours. This gives your cumulative GPA (เกรดเฉลี่ยสะสม) on a 4.0 scale.
Not always. Many US universities accept Thai transcripts directly from well-known institutions like Chulalongkorn, Mahidol, or KMUTT. For others, especially at the graduate level, a WES or ECE evaluation may be required. Always check the specific programme requirements.
First Class Honours (เกียรตินิยมอันดับหนึ่ง) typically requires a cumulative GPA of 3.50 or above, completion within the standard programme duration (usually 4 years), and no F grades on record.
Yes. Both D+ (1.5 GPA) and D (1.0 GPA) are passing grades in Thai universities. However, some programmes require a minimum C or higher in core subjects. Check your programme's requirements for specific courses.

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