Thai Industry Sections Closest to the National Size Mix 2026
In short
Wholesale and retail trade carries Thailand's closest match to the national company size mix, off by just 1.1 points, as of 17 Jul 2026. Administrative and support and professional services follow within 2.7 points. Human health and social work sits furthest from the pattern, deviating by 14.6 points. Only 60.7 percent of its companies are micro against a national 75.1 percent. Electricity and gas carries 2.4 percent large companies, 3.5 times the national share of 0.7 percent. Sector size alone does not decide how closely a section mirrors the whole economy.
Which industry sections match Thailand's national size mix?
Thailand's 1,986,709 sized companies split 75.1 percent micro, 22.2 percent small, 2.0 percent medium and 0.7 percent large, as of 17 Jul 2026 (DBD, 2026). Wholesale and retail trade, the single biggest section with 716,066 companies, tracks that split almost exactly, running 74.0 percent micro, 22.6 percent small, 2.6 percent medium and 0.8 percent large. Summing the gaps across all four bands and halving the total gives a mix deviation index of 1.1 points, the lowest of any section measured. Administrative and support comes next at 2.2 points. Professional, scientific and technical services follows at 2.7 points. Construction sits close behind at 2.9 points. At the far end, human health and social work posts a deviation of 14.6 points. Only 60.7 percent of its 17,294 companies are micro, 14.4 points below the national share. Its small share, at 36.4 percent, runs more than 14 points above the national average. Mining and quarrying is the next furthest at 10.2 points. Real estate follows at 8.5 points.
Mix deviation index by industry section
- Wholesale and retail trade1
- Administrative and support2
- Professional, scientific and technical3
- Construction3
- Accommodation and food service4
- Information and communication4
- Electricity and gas5
- Other services5
- Arts, entertainment and recreation6
- Manufacturing6
- Financial and insurance6
- Transportation and storage7
- Education7
- Water supply and waste management7
- Agriculture, forestry and fishing8
- Real estate9
- Mining and quarrying10
- Human health and social work15
Figures in percentage points from the national size mix.
A lower bar means a section's micro, small, medium and large split looks more like the national economy. Wholesale and retail sits closest, human health furthest.
Company size mix by industry section, ranked by closeness to the national split
| Section | Companies | Micro | Small | Medium | Large | Deviation index |
|---|---|---|---|---|---|---|
| National benchmark | 1,986,709 | 75.1% | 22.2% | 2.0% | 0.7% | 0.0 |
| Wholesale and retail trade | 716,066 | 74.0% | 22.6% | 2.6% | 0.8% | 1.1 |
| Administrative and support | 100,711 | 74.3% | 24.4% | 1.1% | 0.2% | 2.2 |
| Professional, scientific and technical | 138,982 | 77.8% | 21.2% | 0.8% | 0.2% | 2.7 |
| Construction | 283,564 | 78.1% | 20.8% | 1.0% | 0.2% | 2.9 |
| Accommodation and food service | 83,608 | 72.5% | 26.1% | 1.2% | 0.3% | 3.9 |
| Information and communication | 52,537 | 79.2% | 19.3% | 1.1% | 0.4% | 4.1 |
| Electricity and gas | 7,833 | 77.0% | 17.2% | 3.4% | 2.4% | 5.0 |
| Other services | 20,455 | 80.5% | 18.9% | 0.5% | 0.1% | 5.4 |
| Arts, entertainment and recreation | 18,486 | 81.4% | 17.5% | 0.9% | 0.2% | 6.3 |
| Manufacturing | 230,396 | 68.7% | 25.7% | 3.5% | 2.1% | 6.4 |
| Financial and insurance | 35,577 | 80.5% | 15.8% | 2.1% | 1.6% | 6.4 |
| Transportation and storage | 85,303 | 68.8% | 28.6% | 2.1% | 0.5% | 6.5 |
| Education | 13,897 | 81.6% | 17.7% | 0.6% | 0.1% | 6.5 |
| Water supply and waste management | 4,818 | 67.9% | 27.3% | 3.8% | 1.0% | 7.3 |
| Agriculture, forestry and fishing | 19,259 | 82.4% | 14.2% | 2.8% | 0.7% | 8.0 |
| Real estate | 149,618 | 83.6% | 15.3% | 0.8% | 0.3% | 8.5 |
| Mining and quarrying | 8,231 | 85.3% | 12.0% | 2.1% | 0.7% | 10.2 |
| Human health and social work | 17,294 | 60.7% | 36.4% | 1.8% | 1.0% | 14.6 |
Share of companies by DBD size band per section, as of 17 Jul 2026. Public administration, households as employers and extraterritorial organizations are excluded for holding fewer than 40 companies each.
Why the mix differs so much by industry
Distance from the national mix tracks how a sector actually operates, not just its headcount. Wholesale and retail trade sits closest partly because it is the anchor. At 716,066 companies it makes up 36.0 percent of every sized company in the registry, so it pulls the national average toward itself almost by construction. Electricity and gas tells a different story. It runs a large company share of 2.4 percent against a national 0.7 percent, a sector where transmission lines, power plants and gas networks demand capital that a two person shop simply cannot raise, so formal scale is close to a requirement for entry. Manufacturing shows the same logic at a smaller multiple, 2.1 percent large against the same 0.7 percent baseline. Human health and social work runs the opposite pattern. Its micro share of 60.7 percent trails the national 75.1 percent by 14.4 points. Its small share of 36.4 percent runs 14.2 points above the national 22.2 percent. Clinics, dental practices and diagnostic labs commonly register enough staff and equipment to clear the micro threshold without ever approaching medium or large scale, so the sector bunches in the small band instead of spreading across all four. Thai policy debate on small business support has flagged this kind of missing middle, where firms crowd into one narrow band rather than climbing steadily through the size ladder, as a structural feature worth tracking rather than an accident of one sector (TDRI, 2025).
Definitions
- Size band
- DBD's classification of each company into micro, small, medium or large based on filed revenue and asset scale.
- Mix deviation index
- Half the sum of the absolute percentage point gaps between a section's micro, small, medium and large shares and the national shares in the same four bands. It equals the smallest share of a section's companies that would have to move to a different size band for that section to match the national mix exactly. Zero means an identical mix, a higher number means a bigger difference.
- Industry section
- One of the 21 lettered top level groups in Thailand's TSIC industry classification, such as manufacturing or financial and insurance, the finest level DBD names publicly for this data.
- Missing middle
- A pattern where a sector's companies bunch into one or two size bands instead of spreading gradually from micro through large, often cited in Thai SME policy discussion.
Assumptions
- Public administration, households as employers and extraterritorial organizations are excluded from the ranking, each holding fewer than 40 registered companies nationwide.
- The mix deviation index weighs a one point gap in the large band the same as a one point gap in the micro band, even though the large band starts from a much smaller national base of 0.7 percent.
- Wholesale and retail trade makes up 36.0 percent of every sized company in the registry, so part of its closeness to the national mix follows from how heavily it shapes that national average in the first place.
- Size bands reflect each company's most recently filed revenue and asset scale, so a company that has not filed in several years may carry an outdated band.
Methodology
Company counts by size band come from market_tsic_insight, DBD's five digit TSIC classification, rolled up to the 21 lettered industry sections and summed across the count_micro, count_small, count_medium and count_large fields, as of 17 Jul 2026. National shares are the same four counts summed across all sections, matching market_national_insight's total of 1,986,709 sized companies. The mix deviation index for each section is half the sum of the absolute percentage point gaps between that section's four size band shares and the national shares in the same four bands, a standard dissimilarity measure. A value of zero means an identical mix to the national split, and a higher value means a bigger difference. Public administration, households as employers and extraterritorial organizations are excluded from the ranking because each holds fewer than 40 registered companies nationwide, too thin a base for a stable percentage.
How we verified this
- Summed count_micro, count_small, count_medium and count_large across every section equals 1,986,709, matching market_national_insight's total sized company count for the same computed_at timestamp.
- National shares recomputed as 1,492,884 divided by 1,986,709 equals 75.14 percent, 441,008 divided by 1,986,709 equals 22.20 percent, 38,942 divided by 1,986,709 equals 1.96 percent, and 13,875 divided by 1,986,709 equals 0.70 percent, summing to 100.00 percent.
- Wholesale and retail trade deviation index recomputed as half of the sum of absolute gaps, 1.14 plus 0.40 plus 0.64 plus 0.08, divided by two, equals 1.13, rounded to 1.1, confirming it as the lowest of the 18 ranked sections.
- Human health and social work deviation index recomputed as half of the sum of absolute gaps, 14.44 plus 14.20 plus 0.16 plus 0.33, divided by two, equals 14.56, rounded to 14.6, confirming it as the highest of the 18 ranked sections.
- Electricity and gas large share of 2.44 percent divided by the national large share of 0.698 percent equals 3.49, rounded to 3.5 times, confirming the ratio cited in the headline.
References
- Department of Business Development. (2026). Registered juristic persons and size classification aggregates. Ministry of Commerce, Thailand. https://www.dbd.go.th/
- TDRI: Thailand Development Research Institute. (2025). SMEs need ecosystems, not just support. https://tdri.or.th/en/2025/10/smes-need-ecosystems-not-just-support/
Frequently asked questions
Which Thai industry section has a company size mix closest to the national average?
Wholesale and retail trade, with a mix deviation index of just 1.1 percentage points, the smallest gap of any of the 18 comparable industry sections.
Which Thai industry section deviates the most from the national size mix?
Human health and social work, with a deviation index of 14.6 points, driven by a micro share of 60.7 percent against a national 75.1 percent and a small share of 36.4 percent against a national 22.2 percent.
Why does electricity and gas have so many large companies?
Electricity and gas runs a large company share of 2.4 percent, 3.5 times the national share of 0.7 percent, because power generation and gas distribution require capital and infrastructure that few small operators can raise.
What is the national size mix of Thai companies?
As of 17 Jul 2026, Thailand's 1,986,709 sized companies split 75.1 percent micro, 22.2 percent small, 2.0 percent medium and 0.7 percent large.
Cite this page
Chatpong L. (2026). Thai Industry Sections Closest to the National Size Mix 2026. Max Data Insights. https://maxdatathailand.com/insights/thai-industry-sections-closest-to-the-national-size-mix-2026
Data & corrections
Download the data (CSV)Spot something off, or want to ask about the data? Email insights@maxsolutions.co.th. We publish corrections.
Written by
Chatpong L.Founder, Max Data, Max Solutions Co., Ltd.
Chatpong L. leads Max Data, a company-intelligence platform built on Thailand's official business registry. He writes about the structure of the Thai economy using primary registry data. His work covers company formation, industry concentration, and regional business activity.
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This page reports company-level and aggregate statistics only. It names no individuals and makes no claims about any person. Figures are provided for information and may be revised as source data updates.