The cheapest protein in a British supermarket costs about half a penny per gram. The most expensive ways to buy it — protein bars, branded “high protein” snacks — can cost more than twenty times as much for the same nutrient. I know this because I used to be the person buying the expensive kind: £2.20 “protein yoghurts” with 12g of protein that I genuinely believed were good value.
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Then I started dividing price by protein grams, and my shopping changed permanently. This is the data piece: 12 everyday UK foods ranked by cheapest protein per gram, priced from Aldi, Tesco and Asda shelves in late 2026, with the maths shown so you can check my working. No opinions here — just division.
The Only Formula You Need
Forget price per kilogram. The shelf-edge number tells you what the food weighs, not what the protein in it costs. The number that matters divides the price by the grams of protein in the pack:
Worked example with dried red lentils: £1.20 ÷ (1000 × 24 ÷ 100) = £1.20 ÷ 240g of protein = £0.005 per gram — half a penny. That means 30g of protein, a full meal’s worth, costs 15p. Now run the same maths on a £2.50 protein bar with 20g of protein: 12.5p per gram, so 30g costs £3.75. Same nutrient, twenty-five times the price. I run this calculation on my phone in the aisle whenever a “deal” catches my eye, and it has saved me from more bad purchases than any other habit I own.
Cheapest Protein Per Gram: The Full 12-Food Ranking
Here is the ranking, cheapest first. Prices are own-brand from Aldi, Tesco and Asda as of late 2026; protein figures from the nutrition labels:
| Rank | Food | Typical price | Protein in pack | Cost per 30g protein | Per gram |
|---|---|---|---|---|---|
| 1 | Dried red lentils (1kg) | £1.20 | 240g | £0.15 | 0.5p |
| 2 | Dried split peas (500g) | £0.65 | 115g | £0.17 | 0.6p |
| 3 | Peanut butter (1kg) | £2.20 | 300g | £0.22 | 0.7p |
| 4 | Rolled oats (1kg) | £1.05 | 130g | £0.24 | 0.8p |
| 5 | Dried chickpeas (500g) | £0.85 | 95g | £0.27 | 0.9p |
| 6 | Baked beans (4 × 415g) | £1.75 | 83g | £0.63 | 2.1p |
| 7 | Budget whey protein (1kg) | £18.00 | 800g | £0.68 | 2.3p |
| 8 | Frozen chicken breast (1kg) | £5.50 | 235g | £0.70 | 2.3p |
| 9 | Semi-skimmed milk (2 litres) | £1.65 | 70g | £0.71 | 2.4p |
| 10 | Greek-style yoghurt (500g) | £1.10 | 45g | £0.73 | 2.4p |
| 11 | Eggs (10-pack) | £1.55 | 63g | £0.74 | 2.5p |
| 12 | Frozen white fish (500g) | £2.50 | 90g | £0.83 | 2.8p |
Read that top row once more: 30g of protein for 15 pence. The entire top five comes in under 30p per 30g. And notice the cliff between ranks 5 and 6 — the dried pulses and grains live in a different universe from everything else, at under a penny a gram, while the animal staples cluster tightly between 2.1p and 2.8p.
Three Patterns in the Data
Dried pulses and grains dominate, and it is not close. Lentils, split peas, chickpeas and oats take four of the top five spots. They are cheap to grow, cheap to dry, cheap to ship, and nobody spends money marketing them — so almost the entire price is the food itself. The unglamorous corner of the supermarket is the best-value corner.
Animal staples cluster — and that is useful. Beans, whey, chicken, milk, yoghurt, eggs and fish all land between 63p and 83p per 30g. The practical takeaway: among everyday animal proteins, the differences are small enough that you should choose on taste, convenience and nutrition rather than price. Stressing over chicken vs eggs at these margins is not worth your time; both are fine.
The convenience tax is brutal. That £2.20 protein yoghurt I used to buy: 12g of protein at roughly 18p per gram — thirty-six times the cost of lentils. Protein bars are worse. You are not paying for protein; you are paying for packaging, branding and the word “protein” printed large on the front. If the research behind the protein targets these costs serve interests you, Examine.com’s protein intake guide is the most thorough summary I have found.
Where the Ranking Misleads You
Cost per gram is a brilliant metric with genuine blind spots, and I have fallen into every one of them. The ranking gets a food onto your shortlist; it should not make the final decision alone.
Peanut butter’s calories. Third cheapest per gram — but 30g of protein from peanut butter means eating about 600 calories of it. Glorious when you are bulking; catastrophic when you are cutting. Cheap protein wrapped in expensive calories is not always cheap.
Oats’ low density. Fourth cheapest, yet you would need 230g of dry oats — an heroic bowl of porridge — to get 30g of protein. Oats are a brilliant cheap contributor, not a cheap foundation. I use them to carry yoghurt and peanut butter, not to do the heavy lifting alone.
Dried pulses need planning. The cheapest foods of all demand soaking, long cooking, and a digestive system accustomed to the fibre. They reward a little organisation — a Sunday pot of dahl, a soaked batch of chickpeas — and punish spontaneity. Tinned versions cost roughly double per gram but need zero planning; that premium is sometimes worth paying.
Protein quality still matters. The cheapest plant options are slightly lower in one or two essential amino acids than animal proteins. Eating a variety across the day — lentils with rice, peanut butter on toast, beans with grains — covers the gaps completely. The British Nutrition Foundation explains plant protein combining well if you want the detail. My rule: cost per gram picks the shortlist; calories, effort and variety pick the winners.
A Full Day of Eating From the Top of the Table
Time to prove the ranking works as actual food. Here is a full day built deliberately from the cheap end of the list — nothing exotic, everything costed:
| Meal | What (protein source in bold) | Protein | Cost |
|---|---|---|---|
| Breakfast | Overnight oats: 80g oats, 150g Greek yoghurt, milk, peanut butter | 26g | £0.32 |
| Lunch | Split pea soup (100g dried peas), stock, veg, bread | 23g | £0.13 |
| Snack | 3 boiled eggs, fruit | 19g | £0.47 |
| Dinner | 200g frozen chicken breast, rice, frozen veg | 47g | £1.10 |
| Evening | 200g Greek yoghurt, honey | 18g | £0.44 |
| Top-up | Whey shake (30g scoop) in water | 24g | £0.54 |
| Day totals | 157g | £3.00 | |
157g of protein for £3.00 — under 2p a gram for the whole day, and I would happily eat every meal on that list. The split pea soup is the quiet hero: 100g of dried peas costs 13p and delivers 23g of protein. Scale portions to your own target — the protein calculator will set it — and the daily cost barely moves, because the expensive items were never the protein.
Rank Your Own Staples in the Aisle
My prices will drift; the method will not. The Protein Cost Calculator runs the ranking maths on any food in seconds — here is what to feed it:
| What you enter | Where to find it | Example |
|---|---|---|
| Food name | The product as sold | Cottage cheese 300g |
| Price (£) | Shelf edge or receipt | £0.95 |
| Pack weight (g) | The packet | 300g |
| Protein per 100g | Nutrition label | 11g |
That example works out at £0.029 per gram — 2.9p, just above frozen fish in my ranking, which tells you it is a fair but unremarkable buy. I keep a running ranked list in my phone notes of everything I have calculated, cheapest first. When a supermarket “deal” appears, I check it against the list before celebrating. This is general information, not medical advice — if you have a health condition, are pregnant, or take medication, speak to your GP or a registered dietitian before making major dietary changes.
What is the absolute cheapest protein per gram in the UK?
Dried red lentils, at around half a penny per gram — 30g of protein for about 15p, based on a £1.20 kilo bag. Dried split peas are a close second at 0.6p per gram. Prices move a little between supermarkets, but the ranking order is remarkably stable: dried pulses always win.
Is whey protein cheaper than chicken?
Just about — budget whey works out at roughly £0.68 per 30g of protein versus £0.70 for frozen chicken breast, so they are effectively tied. I treat whey as a convenient top-up for porridge and shakes rather than a foundation, since whole foods bring fibre, micronutrients and actual chewing. But as pure protein economics, it earns its place.
Are cheap proteins lower quality?
Not in the way people assume. Eggs, dairy, chicken and fish are complete proteins with excellent amino acid profiles, and they all sit in the cheap half of any honest ranking. The very cheapest options — lentils, peas, chickpeas — are slightly low in one or two amino acids, but eating a variety of plant foods through the day solves that completely. Price reflects farming, processing and marketing far more than nutritional quality.
How much does 150g of protein cost per day on a budget?
About £3 a day built from the top of my ranking — my sample day hit 157g for £3.00. The same 150g built from convenience products, protein bars and fresh fish can easily cost £12–15 a day. The protein is the same; the delivery vehicle is what you are paying for.
Do I need to worry about protein quality with cheap plant foods?
Only enough to eat a variety. No single plant food (except soya) matches the amino acid profile of eggs or meat, but combinations — rice with lentils, hummus with pitta, peanut butter on toast — cover each other’s gaps across the day. You do not need to combine them in the same meal; the body pools amino acids over roughly 24 hours. If you want to see how your protein target balances with carbs and fats, the Macro Split Calculator lays out the full day.
Why are protein bars so expensive per gram?
Because you are buying convenience, branding and shelf life, not protein. A £2.50 bar with 20g of protein costs 12.5p per gram — twenty-five times the cost of lentils. They have their place (my gym bag has one for emergencies), but as a daily protein source they are one of the worst value foods in the supermarket.
