Coffee guides · Evidence-led guide
Why a larger coffee does not always mean more caffeine
The short answer
More liquid does not necessarily mean more coffee. A larger milk-based drink can use the same espresso amount, while another size or drink style changes the shot count.
Dated Costa reference: the recorded guide covers 30 April–26 August 2026. A newer recipe has not been verified; confirm the current menu before relying on an exact amount.
Dated Starbucks UK reference: these records use the Spring 2026 guide. Newer seasonal guides are available; current recipes have not yet been reconciled with this snapshot.
Inspect the documented servings
These values come from the linked catalogue records. A source-backed record is not a measurement of your drink or a guarantee of a current recipe.
| Drink / market | Serving | Caffeine | Per 100 ml | Evidence / action |
|---|---|---|---|---|
| Costa Signature Blend LatteUK | Small, drink in | 100 mg | Not documented | Calculated from manufacturer tableVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Costa Signature Blend LatteUK | Small, takeaway | 200 mg | Not documented | Calculated from manufacturer tableVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Costa Signature Blend LatteUK | Medium | 200 mg | Not documented | Calculated from manufacturer tableVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Costa Signature Blend LatteUK | Large | 325 mg | Not documented | Calculated from manufacturer tableVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Starbucks UK Caffè LatteUK | Short | 44.6 mg | Not documented | Manufacturer listedVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Starbucks UK Caffè LatteUK | Tall | 89.1 mg | Not documented | Manufacturer listedVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Starbucks UK Caffè LatteUK | Grande | 89.1 mg | Not documented | Manufacturer listedVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Starbucks UK Caffè LatteUK | Venti | 133.7 mg | Not documented | Manufacturer listedVerified source record · Reviewed 2026-08-23Use this dose · Compare |
Bars use the selected measure; numbers remain visible in both units. No bar is drawn for an undocumented concentration. Per 100 ml = serving caffeine × 100 ÷ documented volume.
Separate total dose from concentration
Total caffeine answers how much is in the complete serving. Milligrams per 100 ml answers how concentrated it is. Adding liquid without adding caffeine changes concentration but not the total. That arithmetic is useful only when the recipe and liquid volume are actually known.
A concrete recipe example
The dated Costa recipe assigns two espresso shots to both the Small takeaway and Medium Latte, while Small drink-in uses one. The table reflects these named preparations. It does not imply every current small and medium coffee will match them.
Choose the order you actually drink
Compare complete servings for an order decision, and equal volumes for a concentration question. Where millilitres are absent from the source, CaffCalc leaves concentration unavailable. It does not infer volume from milk weight or a size label.
Sources and scope
- Costa Coffee UK store guideGuide applies 30 April–26 August 2026. Source reviewed 2026-08-23.
- Starbucks UK Nutrition & Allergen GuideCore beverage guide version 16 April 2026; Espresso table. Milk substitutions and other customisations can change the finished drink. Source reviewed 2026-08-23.
Educational information, not medical advice. Published, calculated and approximate values have different limits. Check the current product label or recipe when an exact amount matters.