Source-backed comparison
Greggs vs Costa Coffee: Caffeine & Serving Sizes
Compare indicative Greggs coffee figures with dated Costa recipes, keeping serving sizes and source limitations visible.
These Costa figures are from the guide for 30 April–26 August 2026. We haven’t checked a newer recipe yet, so ask Costa or check the latest menu if you need the current amount.
| Measure | Greggs Latte | Costa Signature Blend Latte |
|---|---|---|
| Named serving | Large / 380 g | Large |
| Market | UK | UK |
| Caffeine per serving | 208 mg | 325 mg |
| Caffeine per 100 ml | Not available from source | Not available from source |
| Total sugars per named serving | Not documented for this serving | Not documented for this serving |
| Energy per named serving | Not documented for this serving | Not documented for this serving |
| Value basis | Reported by independent comparison | Calculated from manufacturer table |
| Estimated after 5 hours | 104 mg | 162.5 mg |
| Absolute difference | 117 mg | 117 mg |
| Difference vs lower serving | 56.3% | 56.3% |
How to interpret the comparison
- The opening pair compares named Large lattes, not equal liquid volumes. Greggs is listed at 380 g; no millilitre conversion is inferred.
- Greggs values are indicative supplier figures reported by Which?, not exact measured doses. Costa recipes refer to April–August 2026.
- Use the expanded table to inspect other drinks. These data don’t establish a verified current brand-wide winner.
Guide updated 2026-10-24
Greggs vs Costa coffee: compare the evidence, not just the cup
The short answer
There’s no defensible single winner for all Greggs and Costa coffees. The available records describe different sizes and evidence types: Greggs supplier estimates reported by Which?, and Costa’s dated recipe guide.
These Costa figures are from the guide for 30 April–26 August 2026. We haven’t checked a newer recipe yet, so ask Costa or check the latest menu if you need the current amount.
Compare the serving sizes
These figures come from the sources linked below. Your drink may vary, and recipes can change, so check the latest label or menu if you need an exact amount.
| Drink / market | Serving | Caffeine | Per 100 ml | Evidence / action |
|---|---|---|---|---|
| Greggs EspressoUK | 30 ml shot | 75 mg | 250 mg (calculated) | Reported by independent comparisonIndicative supplier figure · Reviewed 2026-09-04Use this dose · Compare |
| Costa Signature Blend espressoUK | 1 shot | 100 mg | Not documented | Manufacturer listedVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Greggs Flat WhiteUK | 222 ml | 150 mg | 67.6 mg (calculated) | Reported by independent comparisonIndicative supplier figure · Reviewed 2026-09-04Use this dose · Compare |
| Costa Signature Blend Flat WhiteUK | Small | 241 mg | Not documented | Manufacturer listedVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Greggs LatteUK | Large / 380 g | 208 mg | Not documented | Reported by independent comparisonIndicative supplier figure · Reviewed 2026-09-04Use 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 |
| Greggs CappuccinoUK | Large / 327 ml | 235 mg | 71.9 mg (calculated) | Reported by independent comparisonIndicative supplier figure · Reviewed 2026-09-04Use this dose · Compare |
| Costa Signature Blend CappuccinoUK | Medium | 325 mg | Not documented | Calculated from manufacturer tableVerified source record · Reviewed 2026-08-23Use this dose · Compare |
| Greggs AmericanoUK | Large / 382 ml | 257 mg | 67.3 mg (calculated) | Reported by independent comparisonIndicative supplier figure · Reviewed 2026-09-04Use this dose · Compare |
| Costa Signature Blend AmericanoUK | Medium | 325 mg | Not documented | Calculated from manufacturer tableVerified 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 unknown concentration. Per 100 ml = serving caffeine × 100 ÷ listed volume.
A comparison with unequal evidence
Which? reports that Greggs doesn’t measure caffeine and supplied indicative supplier figures as a guide. Costa’s figures come from a manufacturer document with an explicit menu period. Neither source measures the drink in your hand. Comparing their numbers is useful for orientation, but doesn’t tell us a laboratory-tested difference between today’s shops.
Match the drink and the preparation
The Greggs latte record is a Large listed at 380 g; the default Costa latte is a Medium. They aren’t equivalent portions. Grams aren’t converted to millilitres here. Use the product pages to inspect the named servings before making a decision. A plain espresso, flat white and milky latte aren’t interchangeable measures of a brand’s strength.
Why the flat white needs special care
Costa’s recorded flat white uses three Cortissimo extractions. It must not be reconstructed using the ordinary espresso-by-shot table. The Greggs flat white uses a separate supplier estimate. A shot count is meaningful only when its extraction and source are identified.
What to do when ordering now
The Costa guide used here applies to 30 April–26 August 2026. These are documented historical recipes, not a verified current menu. Check the present store recipe before relying on a shot count. Ask about decaf and the actual number and type of shots. If the current recipe cannot be verified, retain an approximate entry rather than upgrading a historical value to an exact current figure. This comparison concerns caffeine quantity, not taste, value, nutrition or personal health effects.
Sources and notes
- Which? high-street coffee comparison (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 doesn’t publish this value, so treat it as a reported figure rather than a first-party public listing. Source reviewed 2026-09-04.
- Costa Coffee UK store guideGuide applies 30 April–26 August 2026. Source reviewed 2026-08-23.
Use this guide to compare drinks, not to make medical decisions. We have marked estimates and calculations so you can tell them apart from published amounts. Check the latest label or menu if you need an exact figure.
Calculated five-hour timeline
This table applies the same exponential half-life equation to both starting amounts. It doesn’t show measured blood levels or predict which drink will affect a particular person more.
| Hours after serving | Greggs Latte | Costa Signature Blend Latte |
|---|---|---|
| 0 | 208 mg | 325 mg |
| 3 | 137.2 mg | 214.4 mg |
| 5 | 104 mg | 162.5 mg |
| 8 | 68.6 mg | 107.2 mg |
| 10 | 52 mg | 81.3 mg |
| 12 | 39.4 mg | 61.6 mg |
Sources
- Indicative supplier figureWhich? high-street coffee comparison (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 doesn’t publish this value, so treat it as a reported figure rather than a first-party public listing.
- Costa Coffee UK store guideGuide applies 30 April–26 August 2026.
Find lower-caffeine alternatives to Greggs Latte or compare drinks against a bedtime target.