Tesco leads the GB grocery market with 27.8% share, followed by Sainsbury's (15.2%), Asda (11.5%) and Aldi (10.5%), in Worldpanel by Numerator (formerly Kantar) data for the 12 weeks to 4 October 2026. The discounters Aldi and Lidl have grown from a combined 10% of the market in 2017 to 19.1% in the 12 weeks to 4 October 2026, taking share almost entirely from the traditional "Big Four" of Tesco, Sainsbury's, Asda and Morrisons, whose combined share has fallen from around 73% in 2017 to 62.8% in the 12 weeks to 4 October 2026.
TL;DR · LAST REVIEWED 14 October 2026
- Tesco is the largest GB grocer with 27.8% market share, followed by Sainsbury's (15.2%), Asda (11.5%) and Aldi (10.5%), per Worldpanel by Numerator (formerly Kantar) data for the 12 weeks to 4 October 2026.
- Aldi overtook Morrisons in September 2022 to become the UK's fourth-largest grocery retailer and has held that position since.
- The traditional "Big Four" (Tesco, Sainsbury's, Asda, Morrisons) held around 73% of the market in 2017; that has fallen to 62.8% in the 12 weeks to 4 October 2026, with almost all the lost share going to discounters Aldi and Lidl.
- Grocery price inflation was 2.5% in the four weeks to 4 October 2026, up from 2.3% four weeks earlier, according to Worldpanel by Numerator (formerly Kantar).
KEY FACTS
- Tesco: 27.8% market share (12 weeks to 4 October 2026), the largest GB grocer
- Sainsbury's: 15.2%; Asda: 11.5%; Aldi: 10.5%; Lidl: 8.6%; Morrisons: 8.3%; Co-op: 5.4%; Waitrose: 4.4%; Iceland: 2.2%; Ocado: 2.2%
- Aldi overtook Morrisons in September 2022 to become the UK's 4th largest grocer
- Big Four combined share fell from ~73% (2017) to 62.8% (12 weeks to 4 October 2026), almost entirely lost to discounters Aldi and Lidl
- Grocery inflation: 2.5% in the four weeks to 4 October 2026, per Worldpanel by Numerator, formerly Kantar
Full UK Grocery Market Share Breakdown
| Tesco | 27.8% | |||
| Sainsbury's | 15.2% | |||
| Asda | 11.5% | |||
| Aldi | 10.5% | |||
| Lidl | 8.6% | |||
| Morrisons | 8.3% | |||
| Co-op | 5.4% | |||
| Waitrose | 4.4% | |||
| Iceland | 2.2% | |||
| Ocado | 2.2% |
Tesco remains comfortably the UK's largest grocer, holding more than a quarter of all grocery spending. Sainsbury's is a clear second, with Asda and Aldi close behind in third and fourth place. The chart above uses Worldpanel by Numerator (formerly Kantar) figures, the industry-standard measure of GB grocery market share, for the 12 weeks to 4 October 2026, published on 13 October 2026.
| Retailer | Market Share | Positioning |
|---|---|---|
| Tesco | 27.8% | Largest overall; Clubcard Prices drive loyalty-based value |
| Sainsbury's | 15.2% | Second largest; Nectar scheme, strong own-label range |
| Asda | 11.5% | Value positioning, but losing ground to discounters |
| Aldi | 10.5% | Discounter; overtook Morrisons in Sept 2022 to become 4th largest |
| Lidl | 8.6% | Fastest-growing bricks-and-mortar retailer, gaining share every year |
| Morrisons | 8.3% | Traditional Big Four member, now challenged by discounters |
| Co-op | 5.4% | Convenience-focused, strong community/local presence |
| Waitrose | 4.4% | Premium positioning, growing faster than the market overall |
| Iceland | 2.2% | Frozen food specialist, value-focused niche |
All figures above come from the Worldpanel by Numerator (formerly Kantar) release for the 12 weeks to 4 October 2026. Lidl (8.6%) now ranks fifth, ahead of Morrisons (8.3%), and Ocado holds 2.2%.
The Bigger Story: Discounters Reshaping the Market
The single biggest structural shift in UK grocery retail over the past decade has been the rise of German discounters Aldi and Lidl at the direct expense of the traditional "Big Four" (Tesco, Sainsbury's, Asda and Morrisons).
| 2010 | ~76% | |||
| 2017 | ~73% | |||
| 2026 | 62.8% |
In 2017, Aldi and Lidl held a combined market share of around 10%. In the 12 weeks to 4 October 2026 they held 19.1% combined (Aldi 10.5%, Lidl 8.6%), nearly double. Aldi crossed a symbolic threshold in September 2022, overtaking Morrisons to become the UK's fourth-largest grocery retailer, a position it has held ever since. The Big Four's combined share, once around three-quarters of the market, has fallen to 62.8%.
Why the Discounters Keep Winning
Aldi and Lidl's growth accelerated sharply during the 2021-2023 cost-of-living crisis, when grocery inflation reached record highs, but the trend predates and has outlasted that specific shock. Both discounters run a leaner model than traditional supermarkets: a smaller range of products (typically 80% of what a full-size supermarket carries), heavy reliance on private-label goods over branded products, and simplified store formats that keep overheads down. That structural cost advantage lets them consistently undercut full-range supermarkets on core grocery items, even as perceptions of discounter quality have improved significantly, drawing in wealthier shoppers who once avoided them by reputation alone.
What This Means for Your Shopping
Tesco and Sainsbury's have responded to discounter pressure with loyalty-card pricing, Clubcard Prices and Nectar Prices respectively, which can bring branded-supermarket prices close to discounter levels on specific promoted items, but only for loyalty scheme members and only on selected products. For a genuinely low weekly shop on staples and own-label basics, Aldi and Lidl remain consistently cheaper on a like-for-like basket. For branded goods, wider product range, or online delivery, the larger supermarkets still have the edge. Co-op and convenience-format stores generally command a price premium in exchange for accessibility and shorter shopping trips.
The Bottom Line
No single supermarket is cheapest for everything. The practical approach most household-budgeting guidance converges on: shop at Aldi or Lidl for weekly staples and own-label basics, use a full-range supermarket's loyalty pricing for branded items you specifically want, and treat convenience-format stores as a top-up option rather than a main weekly shop, given their higher average prices.
RELATED GUIDES
DISCLAIMER
This article is for general information only. Kael Tripton Ltd is an independent editorial publisher and is not authorised or regulated by the Financial Conduct Authority (FCA). Market share figures are sourced from Kantar's published data and can shift from period to period; figures for some retailers reflect the most recent range reported across several Kantar releases rather than a single identical snapshot date. ICO registration ZC135439.
Frequently asked questions
Which UK supermarket has the biggest market share?
Tesco, with 27.8% of the GB grocery market in the 12 weeks to 4 October 2026 according to Worldpanel by Numerator (formerly Kantar), making it comfortably the largest grocer.
Is Aldi bigger than Morrisons now?
Yes. Aldi overtook Morrisons in September 2022 to become the UK's fourth-largest grocery retailer, and has held that position since.
Are Aldi and Lidl actually cheaper than the big supermarkets?
For a typical weekly shop on staples and own-label items, generally yes. Tesco and Sainsbury's can match or beat discounter prices on specific loyalty-card promoted items, but not consistently across a full basket.
How has the UK grocery market changed over the past decade?
The traditional "Big Four" (Tesco, Sainsbury's, Asda, Morrisons) held around 73% of the market in 2017; that has fallen to 62.8% in the 12 weeks to 4 October 2026, with almost all of the lost share going to discounters Aldi and Lidl.
What is UK grocery inflation currently?
2.5% in the four weeks to 4 October 2026, according to Worldpanel by Numerator (formerly Kantar), up from 2.3% four weeks earlier and well below the levels seen during the 2021-2023 cost-of-living crisis.
SOURCES
- Worldpanel by Numerator, GB grocery market share and inflation release (12 weeks to 4 October 2026), published 13 October 2026, accessed 14 October 2026
Update, 14 October 2026: latest Worldpanel grocery market share In the 12 weeks to 4 October 2026, Tesco held 27.8% of the GB grocery market, Sainsbury's 15.2%, Asda 11.5% and Aldi 10.5%, according to Worldpanel by Numerator. Lidl's share rose to 8.6% from 8.2% a year earlier, keeping it ahead of Morrisons at 8.3%, with Lidl sales up 7.1%. Co-op held 5.4%, Waitrose 4.4%, Iceland 2.2% and Ocado 2.2%, with Ocado sales up 12.4%. Like for like grocery price inflation was 2.5% in the four weeks to 4 October 2026, up from 2.3% four weeks earlier, Worldpanel by Numerator reported. Total take home grocery sales grew 1.0% year on year in the same four week period. The figures come from Worldpanel by Numerator. |
