41 PDB statistics [2026]

The Protein Data Bank (PDB) is the central open archive for experimentally determined 3D structures of biological macromolecules. As of June 30, 2026, the RCSB PDB current-holdings API returned 256,006 released PDB entries.

This page collects current PDB statistics from RCSB PDB and wwPDB primary sources. The bullets are written as quote-ready stats, with dates, units, and structured citations.

PDB at a glance

The headline PDB count is a moving number because new structures are released and older entries can be obsoleted. RCSB PDB and wwPDB pages also count related but distinct things: released archive entries, computed structure models, deposits, and downloads.

For current archive size, the cleanest source is the RCSB PDB current-holdings API. For method, molecule, ligand, and file-availability breakdowns, the RCSB PDB statistics summary gives source-linked counts.

• The RCSB PDB Data API returned 256,006 current PDB entry IDs when checked on June 30, 2026.^[1]
• RCSB PDB's live header listed 256,006 structures from the PDB archive and 1,062,058 computed structure models on June 30, 2026.^[8]
• RCSB PDB counted 205,226 X-ray structures, 35,206 EM structures, 14,790 NMR structures, 391 integrative structures, 266 multiple-method structures, 90 neutron structures, and 37 other-method structures, totaling 256,006 entries.^[2]
• RCSB PDB counted 193,851 PDB entries with any non-polymer small molecule and 54,082 entries with author-designated ligands of interest on June 30, 2026.^[2]
• wwPDB recorded 4,720,879,935 PDB coordinate and experimental-data downloads/views in 2025.^[6]

Growth and annual releases

The PDB's growth curve is one of the clearest measures of structural biology output. Annual releases track public archive growth, while depositions measure what researchers submit for processing.

The release totals below use RCSB PDB's live growth table. wwPDB deposition tables are treated separately because they include submitted structures that may later be withdrawn, obsoleted, or released in a different year.

• The PDB began in 1971 with seven protein structures, according to RCSB PDB's history page.^[7]
• RCSB PDB reported 247,251 cumulative released structures at the end of 2025 and 256,006 cumulative released structures in 2026, with 8,755 structures released during 2026 to date.^[3]
• RCSB PDB's live growth table lists 2025 as the largest full release year so far, with 17,616 structures released during 2025.^[3]
• The PDB passed 100,000 cumulative structures in 2014, when RCSB PDB reported 105,050 entries at year-end.^[3]
• The PDB passed 200,000 cumulative structures between 2022 and 2023; RCSB PDB reported 199,677 entries at the end of 2022 and 214,175 entries at the end of 2023.^[3]
• Calculated: the current PDB archive is about 36,572 times larger than its 1971 starting size, because 256,006 current entries divided by seven starting entries equals 36,572.3.^[1][7]

Experimental methods

Experimental method counts show how structural biology has changed. X-ray crystallography still dominates the archive, while electron microscopy now accounts for a large and growing share of current entries.

Percentages in this section are calculated from the RCSB PDB method counts and the 256,006-entry total. Counts by method are exact page counts as accessed on June 30, 2026; percentages are rounded to one decimal place.

• X-ray structures account for 80.2% of current PDB entries, calculated as 205,226 X-ray structures divided by 256,006 total structures.^[2]
• Electron microscopy structures account for 13.8% of current PDB entries, calculated as 35,206 EM structures divided by 256,006 total structures.^[2]
• NMR structures account for 5.8% of current PDB entries, calculated as 14,790 NMR structures divided by 256,006 total structures.^[2]
• Integrative, multiple-method, neutron, and other-method entries together account for 784 structures, or 0.3% of the current archive, calculated as 391 + 266 + 90 + 37 divided by 256,006.^[2]
• RCSB PDB counted 391 integrative structures in the current archive, using its category for structures supported partly or entirely by methods outside the main PDB experimental-method set.^[2]

Molecule types

PDB entries often contain multiple molecule classes in the same structure, so polymer-entity counts and molecular-type counts answer different questions. A protein-DNA complex, for example, can appear in both protein and DNA polymer-entity counts.

Use polymer-entity type stats when you need to know how many entries contain a class of polymer. Use the molecular-type summary when you need mutually grouped archive categories such as protein-only or protein/nucleic acid.

• RCSB PDB's polymer-entity statistics counted 250,783 entries containing protein polymer entities, 13,313 containing DNA polymer entities, 10,138 containing RNA polymer entities, 309 containing nucleic-acid hybrid polymer entities, and 18 containing other polymer entity types.^[4]
• RCSB PDB's molecular-type summary counted 219,606 protein-only entries, 16,589 protein/nucleic acid entries, 14,429 protein/oligosaccharide entries, 5,115 nucleic-acid-only entries, 244 other entries, and 23 oligosaccharide-only entries.^[2]
• Calculated: protein-only entries represent 85.8% of current PDB entries, because 219,606 protein-only entries divided by 256,006 total entries equals 0.858.^[2]
• Calculated: entries containing nucleic acids in the RCSB molecular-type summary total 21,704, because 16,589 protein/nucleic acid entries plus 5,115 nucleic-acid-only entries equals 21,704.^[2]

Ligands and experimental data

Ligand and data-file statistics matter because many PDB users care less about the existence of coordinates than about what can be reused: binding-site structures, structure factors, EM maps, NMR restraints, and chemical-shift data.

These counts come from RCSB PDB's current summary page. They describe entries with associated data or molecule annotations, not the number of distinct ligands, maps, or experiments.

• RCSB PDB counted 193,851 entries with any non-polymer small molecule on June 30, 2026.^[2]
• RCSB PDB counted 54,082 entries with author-designated ligands of interest on June 30, 2026.^[2]
• RCSB PDB counted 195,386 current entries with a structure factor file on June 30, 2026.^[2]
• RCSB PDB counted 11,505 current entries with an NMR restraint file, 6,038 with a chemical-shifts file, and 4,599 with NMR unified data files on June 30, 2026.^[2]
• RCSB PDB reported that 34,635 3DEM maps were used for the determination of 34,886 PDB structures on June 30, 2026.^[2]

Depositions and usage

Deposition statistics describe structures submitted to wwPDB for processing, not necessarily structures released in the same year. Usage statistics count coordinate and experimental-data downloads/views across wwPDB sites.

The latest wwPDB deposition table was last updated on June 23, 2026, while the download table was last updated on June 29, 2026. Those update dates matter because 2026 rows are year-to-date values.

• wwPDB counted 20,975 PDB structures deposited and processed in 2025, with 8,528 deposited to RCSB PDB, 7,053 to PDBj, and 5,394 to PDBe.^[5]
• wwPDB reported that 4,647 principal investigators submitted structures in 2025.^[5]
• Asia was the largest depositor-location category in 2025, with 6,989 PDB depositions, followed by North America with 6,265 and Europe with 6,262.^[5]
• wwPDB counted 10,520 PDB structures deposited and processed in 2026 year-to-date as of the June 23, 2026 update.^[5]
• wwPDB counted 4,720,879,935 PDB data downloads/views in 2025, split into 2,315,511,093 FTP archive events and 2,405,368,842 website events.^[6]
• wwPDB counted 2,386,947,340 PDB data downloads/views in 2026 year-to-date as of the June 29, 2026 update.^[6]
• Calculated: PDB data averaged about 12.93 million downloads/views per day in 2025, because 4,720,879,935 annual events divided by 365 days equals 12,933,917 per day.^[6]

Computed structure models

Computed structure models are displayed alongside PDB entries on RCSB.org, but they are not experimentally determined PDB archive entries. Keeping that distinction clear prevents overcounting.

RCSB's computed-model counts are useful for understanding the scale of predicted structures that users can search on the RCSB site. They should not be substituted for the experimental PDB archive count.

• RCSB PDB listed 1,062,058 computed structure models on June 30, 2026.^[8]
• RCSB PDB's homepage counted 992,732 AlphaFoldDB computed structure models and 69,326 ModelArchive computed structure models on June 30, 2026.^[8]
• Calculated: RCSB PDB lists about 4.15 computed structure models for every experimental PDB archive entry, because 1,062,058 computed models divided by 256,006 current PDB entries equals 4.148.^[8][1]
• Calculated: AlphaFoldDB models make up 93.5% of RCSB PDB's computed-structure-model set, because 992,732 AlphaFoldDB models divided by 1,062,058 total computed models equals 0.935.^[8]

Access, formats, and identifiers

PDB access statistics are also format statistics. The archive's older four-character identifiers and legacy PDB flat files shaped decades of software, but large modern structures and future accession growth require newer conventions.

The most important practical caveat is that "PDB" can mean the archive, the legacy .pdb file format, or a four-character accession code. Current data work should distinguish those meanings.

• wwPDB says PDB entries have been distributed in PDBx/mmCIF format since it became the standard PDB archive distribution format in 2014.^[9]
• wwPDB says the legacy PDB file format has not been modified or extended since November 21, 2012, and is now frozen.^[9]
• wwPDB says entries with more than 62 chains and/or more than 99,999 ATOM records cannot be fully represented in the legacy PDB file format and are available as PDBx/mmCIF-formatted files.^[9]
• wwPDB anticipates that four-character PDB accession codes will be consumed by 2028 and gives the extended 12-character pattern pdb_00001abc as the successor form for an ID such as 1abc.^[10]
• wwPDB states that PDB archive data files are available under the CC0 1.0 Universal Public Domain Dedication.^[11]

Methodology and citation

This article uses current RCSB PDB pages for live archive composition and wwPDB pages for deposition and download statistics. Where a value is calculated, the relevant bullet labels it as calculated and shows the arithmetic in plain English.

Because PDB statistics update frequently, cite the access date with any number from this page. The article does not add a manual source list because the page source list is rendered from frontmatter.

Current archive size was verified by counting the JSON array returned by the RCSB PDB current-holdings API on June 30, 2026; the API returned 256,006 entry IDs.^[1] Method, molecule, ligand, and experimental-data percentages use 256,006 as the denominator because that is the matching current total on the RCSB PDB summary and current-holdings sources.^[2][1]

Deposition counts and release counts are not interchangeable: wwPDB's deposition table includes submitted, processed, withdrawn, or later-obsoleted structures, while RCSB's growth table reports released archive entries.^[5][3]

Suggested citation: ProteinIQ. "41 PDB statistics [2026]." Updated June 30, 2026. Accessed [your access date]. https://proteiniq.io/guides/rcsb-statistics

Sources▼

1. Current PDB entry IDs RCSB PDB Data API · June 30, 2026. https://data.rcsb.org/rest/v1/holdings/current/entry_ids
2. PDB data distribution by experimental method and molecular type RCSB PDB · June 30, 2026. https://www.rcsb.org/stats/summary
3. Overall growth of released PDB structures per year RCSB PDB · June 30, 2026. https://www.rcsb.org/stats/growth/growth-released-structures
4. Distribution by polymer entity type RCSB PDB · June 30, 2026. https://www.rcsb.org/stats/distribution-polymer-entity-type
5. PDB deposition statistics wwPDB · June 30, 2026. https://www.wwpdb.org/stats/deposition
6. PDB download statistics wwPDB · June 30, 2026. https://www.wwpdb.org/stats/download
7. PDB history RCSB PDB · June 30, 2026. https://www.rcsb.org/pages/about-us/history
8. RCSB PDB homepage counts RCSB PDB · June 30, 2026. https://www.rcsb.org/
9. File formats and the PDB wwPDB · June 30, 2026. https://www.wwpdb.org/documentation/file-formats-and-the-pdb
10. Extended PDB ID with 12 characters wwPDB · June 30, 2026. https://www.wwpdb.org/documentation/new-format-for-pdb-ids
11. Usage policies wwPDB · June 30, 2026. https://www.wwpdb.org/about/usage-policies