How many genes do humans have?

Human gene counts are often quoted as fixed facts. They are better understood as estimates from genome annotations: scientific catalogs that decide which stretches of DNA count as genes, what type of gene they are, and how much evidence is needed before they are included.

The concise answer is that humans have about 19,000 protein-coding genes. If we also count non-coding RNA genes, pseudogenes, and other annotated gene features, the number is much larger: about 78,700 annotated genes in the current GENCODE human reference annotation.

How many genes do humans have?

Humans have 19,442 protein-coding genes in GENCODE Release 50. This is the number most people mean when they ask how many genes humans have: genes that can produce proteins. The same release lists 78,733 total annotated genes on the main chromosomes when non-coding genes, pseudogenes, and other gene categories are included. (GENCODE)

These category rows do not sum perfectly to the total because GENCODE also includes immune-system gene segments and other biotypes. The important distinction is between protein-coding genes and all annotated genes. A protein-coding gene is a gene that can be transcribed and translated into a protein, whose sequence is made of amino acids. (GENCODE)

Why is the answer not a single number?

The answer depends on what we count as a gene. A protein-coding gene is not the same thing as a non-coding RNA gene, and a pseudogene is not counted in the same way as a working protein-coding gene. Modern annotations also contain many transcripts: GENCODE Release 50 lists 644,292 transcripts, far more than the number of genes, because one gene can produce multiple transcript forms. (GENCODE)

This is also why a gene count is not the same thing as a protein count. One gene can have multiple transcripts, some transcripts can encode different protein products, and protein abundance depends on cell type and biological context. Gene number also says little about the size of the proteins encoded by those genes: biology includes both small proteins and exceptionally large proteins.

There is still disagreement between major databases. A 2025 comparison of Ensembl/GENCODE, RefSeq, and UniProtKB found 21,871 genes annotated as coding in at least one of the three sets, but only 19,268 were agreed to be coding by all three. The same study found 2,603 genes whose coding status still differed across the three reference sets. (OUP Academic)

Has the estimate changed over time?

Yes. Early expectations were much higher. Around the time of the first draft of the human genome, the Human Genome Project estimated that humans had roughly 30,000 to 35,000 genes. The final genome sequence later lowered this estimate to 20,000 to 25,000. (National Human Genome Research Institute)

The “finished” human genome analysis published in 2004 reduced the estimate further. Researchers confirmed 19,599 protein-coding genes and identified another 2,188 predicted protein-coding segments. (National Human Genome Research Institute)

The long-term trend is clear: as genome annotation improved, the estimated number of human protein-coding genes fell. The surprise was not that humans have many genes, but that humans have relatively few protein-coding genes for such a biologically complex organism.

How does the human gene count compare with other organisms?

Humans do not have an unusually large number of protein-coding genes. We are in the same broad range as many other animals, and some organisms that seem simpler have similar or higher counts. The comparison should use protein-coding or coding genes, because total annotated gene counts vary more depending on whether non-coding genes and pseudogenes are included.

Counts in the table come from GENCODE Release 50 for human, Ensembl Release 116 for the vertebrate and model-animal rows, Ensembl Plants Release 62 for Arabidopsis thaliana, Ensembl Fungi for baker's yeast, and the ProteinIQ E. coli statistics guide for E. coli K-12 MG1655. (GENCODE)

The main lesson is that gene number is not a simple measure of biological complexity. Humans are complex partly because of how genes are regulated, how transcripts are spliced, when and where genes are expressed, how proteins interact, and how cells are organized, not because humans have dramatically more protein-coding genes than other organisms.

How many genes do we have in our body?

Your body does not have a separate gene catalog for each organ. Nearly every cell in a person's body contains the same DNA, and different cell types arise largely because different genes are active or inactive in different cells.

An adult human body contains roughly 30 trillion human cells. That means the body contains trillions of copies of the human genome, not trillions of different human genes.

There is one important caveat: the human body also contains microbes, and microbes have their own genes. Modern human gut microbiome catalogs contain millions of microbial genes or protein sequences; one unified catalog reported more than 170 million such sequences. These genes are in and on the body, but they are not human genes.

Sources▼

1. Human release statistics (v50) GENCODE · June 29, 2026. https://www.gencodegenes.org/human/stats_50.html
2. Human release 50 (GRCh38.p14) GENCODE · June 29, 2026. https://www.gencodegenes.org/human/
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