UK · Coffee & café
How much caffeine is in Pret Flat White?
Not published in the brand’s public UK menu. This figure is reported by Which? and should be treated as approximate.
Which? reported 180 mg for a 237 ml Pret flat white in its August 2026 UK comparison.
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Source and provenance
- Source type
- Independent publisher
- Market
- UK
- Value basis
- Reported by independent comparison
- Source reviewed
- 4 September 2026
- Source version/date
- 25 August 2026
Which? says it asked five chains for caffeine information and used online guides; many figures were obtained through brand press offices. The brand’s public UK menu does not publish this value, so treat it as a reported figure rather than a first-party public listing.
Estimated caffeine remaining over time
These figures apply CaffCalc’s exponential model to the adjusted 180 mg starting value. They are calculations, not measurements of caffeine in a particular person.
| Hours elapsed | 3-hour half-life | 5-hour half-life | 7-hour half-life |
|---|---|---|---|
| 0 | 180 mg | 180 mg | 180 mg |
| 3 | 90 mg | 118.8 mg | 133.7 mg |
| 5 | 56.7 mg | 90 mg | 109.7 mg |
| 8 | 28.3 mg | 59.4 mg | 81.5 mg |
| 10 | 17.9 mg | 45 mg | 66.9 mg |
| 12 | 11.3 mg | 34.1 mg | 54.9 mg |
With the central five-hour model, the estimate falls below 25 mg after approximately 14.2 hours. The faster and slower columns show why one fixed clearance time should not be treated as a personal fact.
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