How Many Registered Voters Does Each Kenyan County Have?

The most recent official county-by-county register is the one used for the August 2022 election: 22,120,458 voters in total, of whom Nairobi City had 2,416,551, Kiambu 1,275,168 and Nakuru 1,055,515, and Lamu, the smallest county, 81,468. The IEBC has not published an updated register by county for 2027. What it has published are the new voters each county added in the April 2026 registration drive, 2,345,476 in all, led by Nairobi with 276,886.

The county table

The figures below are the IEBC's registered voters per county at each of the last three general elections, as compiled in the Elections Observation Group (ELOG) results database, and the new voters each county registered in the Enhanced Continuous Voter Registration (ECVR) Phase I, 30 March to 28 April 2026, from the IEBC's figures published by ELOG. The last column shows the April additions as a share of the county's 2022 register.

A few notes on reading it. ELOG's 2022 county figures include voters registered in prisons, 7,483 nationally according to the IEBC documents Wikipedia cites; without them the 47 counties held 22,102,532. Add the 10,443 voters registered in the diaspora and the 2022 total is 22,120,458. The 2013 and 2017 national totals, 14,388,781 and 19,611,423, are slightly higher than the county sums for the same reason.

The April 2026 numbers are new registrations only. They do not subtract voters who have died, and they leave out transfers between counties and the smaller numbers who registered at IEBC offices outside the drive. So the 2022 figure plus the April figure is not the current register of any county.

What stands out

Five counties, Nairobi, Kiambu, Nakuru, Kakamega and Meru, held 6,364,516 voters in 2022, about 29 per cent of the register. Nairobi alone had 10.9 per cent. That concentration is why presidential campaigns spend so much time in a handful of places, even under a rule that also demands 25 per cent in 24 counties, explained in the 24-county rule.

Between 2013 and 2022 the register in the 47 counties grew from 14,349,896 to 22,110,015. Growth was fastest in Kwale, where the register rose 88 per cent, and in West Pokot, Mandera, Turkana and Tana River, all up close to 80 per cent. It was slowest in Nyeri (35 per cent), Murang'a, Nairobi, Nyandarua and Kirinyaga, all between 35 and 42 per cent.

Most of the growth came before 2017. The county register rose by 5,257,168 between 2013 and 2017, and by only 2,502,951 between 2017 and 2022.

April 2026: who added most, relative to size

In raw numbers, the April drive followed population: Nairobi, Kiambu, Nakuru, Kakamega and Machakos added the most. Measured against the 2022 register, the pattern changes. Turkana's April intake equalled 24.5 per cent of its 2022 register, Samburu's 19.4 per cent and West Pokot's 18.0 per cent. At the other end, Nyandarua added 5.7 per cent and Embu 6.9 per cent.

Some of that is not about enthusiasm. The IEBC did not run the April drive in six areas with by-elections or petitions pending: Ol Kalou in Nyandarua, Mbeere North in Embu, Malava in Kakamega, Emurua Dikirr in Narok, and Endo and Porro wards. Ol Kalou's catch-up drive runs from 21 September to 20 October 2026, as covered in the Ol Kalou registration drive. The national picture, including the 2,936,516 new voters counted by 20 August, is in IEBC's registration figures.

Registered is not the same as eligible

A county's register counts people who signed up, not everyone old enough to vote, and the two numbers can be far apart. The IEBC's target for 2027 is about 28.5 million registered voters, against 22.1 million in 2022. The difference between registered and eligible is explained in registered voters and eligible voters.

When the next county figures come out

The register for 2027 has to be audited and certified before the election. The IEBC said on 20 August 2026 that an independent firm would carry out a forensic audit first, and the Parliamentary Budget Office said the audit is planned for January to March 2027. The opposition wants the register published by 10 March 2027, as set out in why the opposition wants an audit. Until then, the 2022 county figures above remain the official baseline. How each county voted on that register is in the 2022 results by county.