Women make up nearly half of US workers but a smaller share of STEM jobs: the Census Bureau puts women at 27% of STEM workers in 2019, while the National Center for Science and Engineering Statistics (NCSES) puts them at 35% in 2021. The two figures differ mainly because they define the STEM workforce differently.
That gap between two official numbers is the first thing worth understanding, because articles quote whichever one suits their point. Both agree on the big picture: women have made large gains since 1970, but the biggest STEM fields, computing and engineering, are still mostly male.
Here's what each source measures, where women are well represented, where they aren't, and what that means if you're a woman considering a STEM career or an employer trying to hire one.
Why the official numbers differ
| Source | Women's share | Year | What it counts |
|---|---|---|---|
| US Census Bureau (American Community Survey) | 27% | 2019 | STEM occupations such as computer, engineering, maths and science roles |
| NCSES, Diversity and STEM 2023 | 35% | 2021 | A broader STEM workforce including science and engineering, related occupations and middle-skill jobs |
| NCSES, college-educated science and engineering jobs only | 29% | 2021 | Workers with at least a bachelor's degree in science and engineering occupations |
NCSES says women's share of the STEM workforce rose from 32% in 2011 to 35% in 2021. Neither number is wrong. If someone quotes a figure, ask which definition they used.
For a career decision, the narrower 29% figure for college-educated science and engineering jobs is often the most useful, because it's closer to the graduate roles most people are weighing up.
Long-term progress
The Census Bureau's 2021 analysis tracks change since 1970. Women were 8% of STEM workers in 1970 and 27% in 2019. Over the same period women went from 38% of all US workers to 48%. So women's share of STEM grew faster than their share of the workforce, but it still lags well behind.
The Census Bureau counted nearly 10.8 million workers in STEM occupations in 2019, and says STEM occupations account for nearly 7% of all US occupations.
Where women are, and aren't, represented
| Field (Census, 2019) | Women's share |
|---|---|
| Social science | 64%, up from 19% in 1970 |
| Math occupations | 47% |
| Life and physical science | 45% |
| Computer occupations | About a quarter |
| Engineering | 15% |
This is the insight most headlines skip. The Census Bureau says computer and engineering occupations make up 80% of the STEM workforce, and that's exactly where women's gains have been smallest. Women are close to parity in maths and the sciences, and a majority in social science, but those are the smaller fields. The overall figure is held down by the two biggest ones.
What it means if you're a woman considering STEM
- Look past the headline percentage to the specific field. Your experience in a social science role will differ from one in engineering.
- Ask employers for their own numbers, by team and by level, not just company-wide.
- Look for skills-based routes in, including apprenticeships and technical roles, not only degrees.
- Find communities and mentors early. Being one of few women on a team is easier with a network outside it.
If you're exploring practical routes in, my guide to blue collar jobs for women covers technical trades with some of the same skills gaps, and my roundup of careers for women that pay well includes several STEM-adjacent options.
Representation is only one measure
A share of jobs doesn't tell you about pay, progression or who stays. Those vary by employer and by team, and the official headline figures don't break them down for you. If you're already in STEM, benchmark your pay against official salary data for your exact role, ask how salaries and promotions are decided, and negotiate with numbers rather than instinct.
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It's also worth knowing the base you're starting from. The Census Bureau's 2019 figure covers every worker in a STEM occupation, at every level, so a team's mix of junior and senior staff can look very different from the national average. Ask for the breakdown before you draw conclusions about any one company.
What employers can do
- Measure representation by role and seniority, not only overall.
- Write job ads around the skills the role needs, and drop requirements that aren't essential.
- Widen where you recruit, including career changers and apprentices.
- Track who leaves and why. Representation falls when women don't stay, not only when they don't apply.
- Make flexible working and clear progression the norm, not a favour.
How to use these numbers well
- Quote the source and year with any percentage.
- Say which definition of STEM it uses.
- Compare like with like across years and countries.
A note on the UK and elsewhere
This guide uses US government figures because they're published with clear definitions. Other countries measure STEM differently, so don't compare a US percentage with a UK or Australian one without checking what each counts. The same lesson applies: find out what's being measured before you trust the number.
My verdict
Women in STEM is a story of real progress and stubborn gaps, and the gaps sit in computing and engineering, the fields with the most jobs. If you're a woman weighing a STEM career, pick the field, not the acronym, and look hard at the employer's own record. If you're hiring, measure by team and fix retention as well as recruitment. And whenever you see a single percentage quoted, ask which definition it came from. For inspiration, my list of famous women entrepreneurs includes founders who built their businesses in tech.
Frequently asked questions
What percentage of STEM workers are women?
It depends on the definition. The US Census Bureau says 27% in 2019, while NCSES says 35% of the broader STEM workforce in 2021.
Why do sources give different figures for women in STEM?
They define the STEM workforce differently. NCSES includes science and engineering related jobs and middle-skill occupations, which raises the share.
Which STEM fields have the fewest women?
Engineering and computer occupations. The Census Bureau says women were 15% of engineering workers and about a quarter of computer workers in 2019.
Which STEM fields have the most women?
Social science, where women were 64% of workers in 2019, followed by maths at 47% and life and physical science at 45%.
Has the share of women in STEM grown?
Yes. Women were 8% of STEM workers in 1970 and 27% in 2019, according to the Census Bureau.
