Convert Thai Grades to US GPA

4.0 GPA, 0.00 to 4.00, with 7 bands and a pass mark of 1.00.

There is no official conversion. Credential evaluators and individual universities publish tables that disagree, and they disagree most at the top of the scale. The classification below is a fact from your transcript; the 4.0 figure beside it is the common convention, not a verdict.

A Thai grade

C+ (Fairly Good)

on the Thai scale — this is what the transcript says

US GPA (approx.): 2.3
US letter: C+
Locally: Passing
Band: 2.50–2.99

lowest 63% of the way up the scale highest

The conventional mapping used by US admissions offices. It is not an official conversion — no such thing exists — and the receiving institution's own table is the one that counts.

The full Thai scale

Thailand grade bands and their conventional US equivalents
Grade	Local classification	US	GPA
3.50–4.00	A (Excellent)	A	4.0
3.25–3.49	B+ (Very Good)	B+	3.3
3.00–3.24	B (Good)	B	3.0
2.50–2.99	C+ (Fairly Good)	C+	2.3
2.00–2.49	C (Fair)	C	2.0
1.00–1.99	D (Poor / Pass)	D	1.0
0.00–0.99	F (Fail)	F	0.0

How the Thai scale works

Thai universities grade on a 4.0 scale that mirrors the US one, so the figure carries over almost unchanged.

In practice the scale runs from 0.00 to 4.00 with 7 named bands. The best is A (Excellent) (3.50 to 4.00), and the lowest passing grade is D (Poor / Pass) at 1.00. Anything past that is a fail, whatever the number looks like to a US reader.

The reason a single conversion number does not exist is that the two systems measure different things. A US GPA is an average of course grades on a scale where the top is routinely awarded. Most national scales reserve their top band for a small fraction of students, so mapping the numbers proportionally compresses a whole cohort into the bottom half of the 4.0 range. Band mapping — what this page does — avoids that, but every evaluator draws the bands slightly differently.

Frequently asked questions

What is a Thai 2.50 in US GPA?

It falls in the C+ (Fairly Good) band, which US admissions offices conventionally read as a C+, about 2.3 on a 4.0 scale. Use the calculator above for any other grade. The classification is the part that is certain — the 4.0 number is an approximation, and different evaluators place the boundary in different places.

Is there an official Thai to US GPA conversion?

No. WES, Scholaro, ECE and individual university admissions offices all publish different tables, and they disagree most sharply at the top of the scale where it matters most for applications. Anyone presenting a single figure as the official answer is overstating what exists. Submit your transcript with its classification; the receiving institution applies its own table.

How does the Thai grading scale work?

4.0 GPA, running from 0.00 to 4.00. The pass mark is 1.00, and the highest classification is A (Excellent). Thai universities grade on a 4.0 scale that mirrors the US one, so the figure carries over almost unchanged.

Should I convert my grades myself before applying?

Usually not. Most US universities either evaluate the transcript themselves or require a report from a credential evaluation service, and a self-calculated GPA on an application carries no weight either way. What this page is useful for is knowing roughly where you stand before you commit to an application fee.

Local classifications follow each country's national qualifications framework or ministry of education grading regulations; the US letter column follows the convention common to US credential evaluation.

There is no official conversion from a national grade to a US 4.0 GPA. Credential evaluators and individual universities publish tables that disagree, most of all near the top of each scale. Treat the figure here as the common convention and the local classification as the fact; the receiving institution's own table is the one that decides.