Cheapest Protein Per Gram UK
Tub price is misleading. UK protein ranked by real cost per gram of protein, checked against live retailer prices in August 2026.
Kevin, founder of WheyWise
Quick answer
The cheapest protein per gram in the UK is NutriSport 90+ at about 1.55p per gram of protein in the 5kg bag, with Bulk Basic Whey the recognisable-brand alternative at roughly 1.83p. Neither needs a discount code. The brands people assume are cheapest no longer are: as of August 2026 MyProtein Impact Whey is about 4.15p per gram of protein and Bulk Pure Whey 3.83p, and only a deep code brings either near 2p. Tub price is misleading, so rank on cost per gram of protein rather than the sticker.
Most people compare protein powder prices by looking at the total cost of the bag. That's the wrong metric. A £30 bag can be better or worse value than a £50 bag depending on how much protein is actually in it and how heavy the bag is.
The number that matters is: how much does it cost per 100g of powder? Here's how the major UK brands stack up.
The methodology
Every figure below divides the retailer price by the grams of protein actually in the bag, not by the weight of the powder. Bag weight multiplied by protein per 100g gives total protein; price divided by that gives cost per gram. It is the only number that survives a comparison between a 76% powder in a 5kg sack and a 68% powder in a 1kg tub.
Prices were checked against the retailer on 3 August 2026 and are everyday prices, not sale prices, unless stated. For a live view, use the cheapest protein powder ranking.
Whey concentrate (budget tier)
This is still where the best value lives, but the names at the bottom of the range have changed. Ranked by cost per gram of protein:
| Product | Protein /100g | Cost /g protein | Per 25g protein |
|---|---|---|---|
| NutriSport 90+ (5kg) | 76g | 1.55p | 39p |
| Bulk Basic Whey (2.5kg) | 72g | 1.83p | 46p |
| CNP Whey (2kg) | 71g | 2.04p | 51p |
| NXT Pure Whey Deluxe (2.1kg) | 80.7g | 2.42p | 60p |
| Bulk Pure Whey (2.5kg) | 71g | 3.83p | 96p |
| MyProtein Impact Whey (4.5kg) | 72g | 4.15p | £1.04 |
Everyday prices checked 3 August 2026, no discount codes applied. A full 50% Impact Week code takes MyProtein Impact Whey to roughly 2.08p per gram, which is still above Bulk Basic Whey's everyday price. See the whey concentrate comparison for today's figures.
Cheapest per gram
NutriSport Nutri Sport 90+ Protein 2.5kg
2.5kg bag
NutriSport 90+ is the cheapest UK whey we would actually recommend: a 76g-per-100g isolate and casein blend at roughly 39p per 25g of protein in the 5kg bag, backed by 846 verified reviews. It spends its budget on protein rather than flavour, so expect a plain shake.
Buy Nutri Sport 90+ Protein 2.5kg →Live price across UK retailersCheapest per gram
Pros
- + 76g protein per 100g, whey isolate and micellar casein blend
- + Cheapest credible cost per gram in the UK, about 39p per 25g in the 5kg
- + 4.45/5 from 846 verified reviews at London Supplements
- + UK manufacturer running since the 1980s, no marketing premium
Cons
- – Taste and texture are plain, reviewers call it acceptable not enjoyable
- – Little brand presence, so fewer flavour options than the big names
- – Best price needs the 5kg bag from a discount stockist
●Nutrition per scoop · 27g protein in 30g▼
Protein makes up 90%
of this 30g scoop · 113 kcal total
Cheapest big brand
Bulk Basic Whey Protein
1.25kg bag
Bulk Basic Whey is the entry tier most Bulk buyers walk past: 72g protein per 100g at around 46p per 25g, roughly a third cheaper per gram than Pure Whey from the same manufacturer. The budget pick if you want a name you recognise.
Buy Basic Whey Protein →Live price at Bulkor compare all UK prices →Cheapest big brand
Bulk Basic Whey Protein
1.25kg bagPros
- + Around 46p per 25g, roughly a third cheaper per gram than Bulk Pure Whey
- + 72g protein per 100g from the same manufacturer and quality controls
- + Big-brand returns policy and customer service
- + 2.5kg bag is the value sweet spot
Cons
- – Shorter flavour list than Pure Whey
- – Plainer formula with no Informed Sport testing on this tier
- – Best prices are on marketplace listings rather than direct
●Nutrition per scoop · 21.6g protein in 30g▼
Protein makes up 72%
of this 30g scoop · 112 kcal total
Whey isolate (mid tier)
Isolate is more processed - lower fat, lower lactose, higher protein per 100g (typically 85–92g). It has been hit harder by the whey price rise than concentrate has: expect roughly £2.40–3.80/100g of powder, or about 2.7p to 4p per gram of protein. Naughty Boy ISO-9 is the cheapest we track at around 2.67p per gram. Browse current whey isolate prices to find the cheapest.
Whether the premium is worth it depends on your situation. If you're lactose sensitive or tracking macros very tightly, yes. If you're just trying to hit a daily protein target cheaply, concentrate is fine.
Bulk Natural Pure Whey Isolate
1kg bag
High-purity whey isolate from Bulk with 27g protein per 30g scoop. Very low fat and lactose, ideal for calorie-conscious or lactose-sensitive buyers.
Buy Natural Pure Whey Isolate →Live price at Bulkor compare all UK prices →Pros
- + 27g protein per 30g serving
- + Very low fat and carbs
- + Suitable for lactose-intolerant
- + Mixes thin and smooth easily
Cons
- – Pricier than concentrate version
- – Thinner mouthfeel less satisfying
- – Fewer flavour options
●Nutrition per scoop · 25.2g protein in 30g▼
Protein makes up 84%
of this 30g scoop · 105 kcal total
Casein (slow-release)
Casein digests slowly, which is why it's popular as a before-bed protein. It's typically more expensive than whey concentrate - around £2.00–2.80/100g. Optimum Nutrition Gold Standard Casein is the market leader and can be good value via Amazon when on promotion. Compare casein protein prices across UK retailers.
Vegan protein
Plant-based protein is almost always more expensive per 100g than whey, partly due to processing cost and partly because the market is smaller. Expect £2.00–3.50/100g for a decent pea/rice blend. MyProtein's vegan blend is among the cheaper options. See the vegan protein comparison for the full list.
The honest conclusion
If price per gram is the only thing you care about, buy the 5kg bag of NutriSport 90+ from a discount stockist at about 1.55p per gram of protein. If you would rather stick to a brand you recognise, Bulk Basic Whey at roughly 1.83p is the one to buy, and it is a third cheaper per gram than the Bulk Pure Whey most people reach for by default.
What has changed since this guide was first written is worth stating plainly: buying the biggest bag of MyProtein Impact Whey on a discount code is no longer the cheapest route to protein in the UK. Raw whey went from under $4 a pound in 2023 to about $11, and the direct-to-consumer brands passed it through. A full 50% code lands Impact Whey around 2.08p per gram, which is still above what Bulk Basic Whey and NutriSport charge every day.
Check the live comparison table for today's prices - I update it weekly so the numbers above may have changed. For today's discounted products, see the latest protein powder offers. For a broader value guide, read best protein powder UK 2026.
Cost per gram FAQs
How do I compare protein powders by cost per gram of protein?
Divide the price by the grams of protein in the tub, not by the weight of the powder. Multiply the bag weight by the protein percentage to get total grams of protein, then divide the price by that number. WheyWise does this automatically and ranks every UK product by cost per 100g of powder and cost per 25g of protein.
What is the cheapest protein per gram in the UK?
NutriSport 90+ in the 5kg bag, at about 1.55p per gram of protein as of August 2026. Bulk Basic Whey is roughly 1.83p and CNP Whey about 2.04p, none of them needing a code. MyProtein Impact Whey and Bulk Pure Whey are now about 4.15p and 3.83p per gram, reaching around 2p only on a full 50% code.
Which whey protein brands offer the best price-to-protein ratio?
NutriSport, Bulk's entry-level Basic Whey line and CNP, all between roughly 1.55p and 2.04p per gram of protein at everyday prices. NXT Pure Whey Deluxe gives the most protein purity per pound at 80.7g per 100g for about 2.42p per gram.
Is a bigger bag of protein always cheaper per gram?
Usually yes. Cost per 100g drops sharply on larger bags, so a 2.5kg or 5kg bag is normally far better value per gram than a 1kg tub of the same product.
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1,958 products compared across 85+ UK retailers
Updated weekly. Sorted by best value per 25g of protein.
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