Flat Iron calories: the full UK menu (2026)
Maclo holds 19 Flat Iron menu items with calories, verified against Flat Iron's published nutrition data on 24 Aug 2026. The lightest main that is still a meal is the Flat Iron Steak at 325 kcal; the highest-protein one-person main is Smashed Onion Double Cheeseburger (796 kcal). The protein, carbs, fat and menu prices for every item are blurred on this page and unlock in the Maclo app.
On 19 of these items the brand published calories only; the app names its macro estimate for them as an estimate.
Highlights at Flat Iron
Flat Iron mains average 512 kcal, and 2 of them are under 500 kcal; 2 carry 30 g protein or more.
Browse Flat Iron by goal
The full Flat Iron menu
Every calorie figure is per serving as Flat Iron publishes it. The protein, carbs, fat and menu price columns are blurred here and unlock in the Maclo app.
Mains (3 items)
| Item | Calories | Protein | Carbs | Fat | Menu price | Tags |
|---|---|---|---|---|---|---|
| 35 Day Aged Ribeye | 416 kcal | g | g | g | £ | Calorie verifiedGluten-freeDairy-free |
| Flat Iron Steak | 325 kcal | g | g | g | £ | Calorie verifiedGluten-freeDairy-free |
| Smashed Onion Double Cheeseburger | 796 kcal | g | g | g | £ | Calorie verified |
Sides (6 items)
| Item | Calories | Protein | Carbs | Fat | Menu price | Tags |
|---|---|---|---|---|---|---|
| Creamed Spinach | 425 kcal | g | g | g | £ | Calorie verifiedVegetarianPescatarian |
| Crispy Bone Marrow Garlic Mash | 543 kcal | g | g | g | £ | Calorie verified |
| Green Salad | 210 kcal | g | g | g | £ | Calorie verifiedVeganVegetarianPescatarianDairy-free |
| Homemade Beef Dripping Chips | 490 kcal | g | g | g | £ | Calorie verified |
| Roast Aubergine | 420 kcal | g | g | g | £ | Calorie verifiedVegetarianPescatarianGluten-free |
| Truffled Macaroni Cheese | 525 kcal | g | g | g | £ | Calorie verifiedVegetarianPescatarian |
Drinks (6 items)
| Item | Calories | Protein | Carbs | Fat | Menu price | Tags |
|---|---|---|---|---|---|---|
| Apple & Rhubarb House Fizz | 70 kcal | g | g | g | £ | Calorie verifiedVeganVegetarianPescatarianDairy-free |
| Citrus Margarita (0%) | 91 kcal | g | g | g | £ | Calorie verifiedVeganVegetarianPescatarianDairy-free |
| Lime & Mint House Fizz | 52 kcal | g | g | g | £ | Calorie verifiedVeganVegetarianPescatarianDairy-free |
| Rose Lemonade House Fizz | 58 kcal | g | g | g | £ | Calorie verifiedVeganVegetarianPescatarianDairy-free |
| Sober Mule (0%) | 54 kcal | g | g | g | £ | Calorie verifiedVeganVegetarianPescatarianDairy-free |
| Virgin Passion Fruit Collins | 86 kcal | g | g | g | £ | Calorie verifiedVeganVegetarianPescatarianDairy-free |
Extras (4 items)
| Item | Calories | Protein | Carbs | Fat | Menu price | Tags |
|---|---|---|---|---|---|---|
| Bearnaise Sauce | 195 kcal | g | g | g | £ | Calorie verifiedExtra |
| Homemade Smoked Chilli Mayo | 210 kcal | g | g | g | £ | Calorie verifiedVegetarianPescatarianGluten-freeExtra |
| Peppercorn Sauce | 55 kcal | g | g | g | £ | Calorie verifiedVegetarianPescatarianGluten-freeExtra |
| Wild Mushroom Sauce | 55 kcal | g | g | g | £ | Calorie verifiedVegetarianPescatarianGluten-freeExtra |
Branches in London
Maclo maps 15 London branches of Flat Iron. Open the app to see which branch is nearest, what it charges, and what fits your day.
Common questions about Flat Iron nutrition
How many calories are in Flat Iron meals?
Flat Iron mains average 512 kcal. 2 mains come in under 500 kcal. Maclo holds calories for all 19 items on this page.
What is the highest-protein item at Flat Iron?
Smashed Onion Double Cheeseburger, at 796 kcal. Its protein figure, with the carbs, fat and menu price, unlocks in the Maclo app.
What is the lowest-calorie meal at Flat Iron?
Flat Iron Steak, at 325 kcal, among the mains that still carry at least 15 g protein.
Does Flat Iron publish nutrition information?
0 of the 19 items here carry Flat Iron's own published calories, protein, carbs and fat. This page shows the calories; the Maclo app unlocks the rest. On 19 items Flat Iron publishes calories only.
Where does this data come from?
Flat Iron's published nutrition information at flatironsteak.co.uk, captured 24 Aug 2026. Figures are per serving as the brand states them.
Unlocked in the app
Flat Iron's protein, carbs, fat and prices, unlocked.
This page shows calories. The Maclo app shows everything for every Flat Iron item, ranked against your own targets.
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Maclo is a free iOS app that holds the full protein, carbs, fat and menu price for every item on 140+ UK restaurant menus, ranks them against your calorie and protein targets, prices meal deals as the till does, maps every menu, and logs what you eat in one tap.
Source: flatironsteak.co.uk · captured 24 Aug 2026 · calories are per serving as Flat Iron states them. How this data is collected.
Not affiliated with any restaurant. Brand names belong to their owners. Calorie figures are per serving as published by each brand; recipes and portions change, so check with the restaurant if a figure is critical to you. Corrections: hello@maclo.app.