UK · Coffee & café
How much caffeine is in Starbucks UK Flat White?
89.1 mgManufacturer listed · Short
The Starbucks UK guide lists 89.1 mg for the standard Short Flat White.
Source and provenance
- Source type
- Manufacturer
- Market
- UK
- Value basis
- Manufacturer listed
- Source reviewed
- 21 August 2026
- Source version/date
- 16 April 2026
Guide version 16 April 2026; standard recipe before customisation.
Estimated caffeine remaining over time
These figures apply CaffCalc’s exponential model to the 89.1 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 | 89.1 mg | 89.1 mg | 89.1 mg |
| 3 | 44.5 mg | 58.8 mg | 66.2 mg |
| 5 | 28.1 mg | 44.5 mg | 54.3 mg |
| 8 | 14.0 mg | 29.4 mg | 40.3 mg |
| 10 | 8.8 mg | 22.3 mg | 33.1 mg |
| 12 | 5.6 mg | 16.9 mg | 27.2 mg |
With the central five-hour model, the estimate falls below 25 mg after approximately 9.2 hours. The faster and slower columns show why one fixed clearance time should not be treated as a personal fact.