Cheapest Protein Per Gram UK: The Best Pick for Each Type of Protein
The cheapest protein per gram in the UK is NutriSport 90+, at about 1.7p per gram of protein in the 5kg bag on Amazon UK. If you want 100% whey, Applied Nutrition Critical Whey is the cheapest at about 3.8p. Below is the best-value pick for each type of protein, worked out from each label.
Kevin, founder of WheyWise
About 2.8p per gram from a brand site
Protein Works
Whey Protein 360 Black
2.4kg bag
Buy Whey Protein 360 Black →Direct from Protein Works
10% off with code WHEYWISE
Prozis
Supreme Whey Protein
907g bag
Buy Supreme Whey Protein →Direct from Prozis
Quick answer
The cheapest protein per gram in the UK is NutriSport 90+, at about 1.7p per gram of protein in the 5kg bag on Amazon UK (£63.99). That is a blend of whey, casein, soy and rice protein, which is part of why it is so cheap. If you want whey and nothing else, Bulk Pure Whey costs about 4.2p per gram in its 5kg bag. The simple rule: divide the price by the grams of protein in the bag, not by the weight of the bag, and the cheapest options for each type are below.
If you want every powder ranked in order, see our monthly cheapest protein powder ranking.
For the cheapest powders we would actually buy, ranked by cost per 25g of protein, see our best cheap protein powder UK guide.
What is the cheapest protein per gram for each type?
NutriSport 90+ is the cheapest protein per gram overall, at about 1.7p. The best-value pick changes with what you want from your powder, so here is one for each type.
| If you want | Our pick | Price per gram of protein | Per 25g shake |
|---|---|---|---|
| The lowest price, full stop | NutriSport 90+, 5kg (Amazon UK) | 1.7p | 42p |
| A brand you know, cheaply | Bulk Basic Whey, 2.5kg (Amazon UK) | 2.6p | 64p |
| To buy from the brand's own site | Protein Works Whey Protein 360 Black, 4.8kg | 2.8p | 71p |
| 100% whey, no soy | Applied Nutrition Critical Whey, 2kg (Amazon UK) | 3.8p | 95p |
| Slow-release casein for the evening | Protein Works 100% Micellar Casein, 4kg | 3.4p | 84p |
| Whey isolate, for less lactose | Bulk Pure Whey Isolate, 2.5kg (Amazon UK) | 5.2p | £1.30 |
Retailer one-off prices, without codes or subscriptions, checked in late October 2026. Protein per 100g is from each label, using the lowest-protein flavour. Vegan protein has its own section below.
How do you work out the cost per gram of protein?
Work out how much protein is in the bag, then divide the price by it. You need the price, the bag weight and the protein per 100g from the nutrition label.
- Bag weight in grams × protein per 100g ÷ 100 = grams of protein in the bag.
- Price ÷ grams of protein = cost per gram of protein.
For example, a 5kg bag of NutriSport 90+ has 76g of protein per 100g, so it holds 3,800g of protein. At £63.99, that is about 1.7p per gram.
Multiply by 25 and you get the cost of a 25g protein shake: 42p. We use 25g because the International Society of Sports Nutrition suggests 20g to 40g of protein per serving for people who train (ISSN position stand on protein and exercise, 2017). Our cost per serving guide has more worked examples.
What is the cheapest everyday whey per gram?
NutriSport 90+ gives you the most protein for your money, at about 1.7p per gram in the 5kg bag. It is a blend of whey, casein, soy and rice protein, and it has 76g of protein per 100g, so a scoop is not padded out.
Bulk Basic Whey is the cheaper well-known name at about 2.6p per gram, but it has only 56g of protein per 100g, so you need a bigger scoop. Protein Works Whey Protein 360 Black is the cheapest from a brand's own website at about 2.8p per gram at its one-off price.
Cheapest protein per gram
NutriSport 90+ Protein
5kg bag
The lowest price per gram of protein we found, if a blend suits you.
Buy 90+ Protein →See the price on AmazonCheapest protein per gram
NutriSport 90+ Protein
5kg bagPros
- + About 1.7p per gram of protein in the 5kg bag
- + 76g of protein per 100g
Cons
- – A blend that includes soy and rice protein
- – You need to get through 5kg for the lowest price
●Nutrition per scoop · 45.6g protein in 60g▼
Protein makes up 76%
of this 60g scoop · 214 kcal total
Which 100% whey is cheapest per gram?
If you want whey and nothing else, Applied Nutrition Critical Whey is the cheapest we found at about 3.8p per gram of protein in the 2kg bag on Amazon UK. Its protein is whey concentrate, whey isolate, hydrolysed whey and milk protein. Bulk Pure Whey is next at about 4.2p per gram in the 5kg bag.
A 100% whey costs more per gram because blends with soy are cheaper to make, not because the whey is better for building muscle.
Which whey isolate is cheapest per gram?
Bulk Pure Whey Isolate is the cheapest isolate we checked, at about 5.2p per gram of protein in the 2.5kg bag on Amazon UK, against about 6.1p for Myprotein Impact Whey Isolate in its 2.7kg bag.
Isolate is filtered to remove most of the lactose and fat, so it is worth paying for if regular whey upsets your stomach. If it doesn't, a whey concentrate gives you the same protein for less. Our best whey isolate guide covers the rest.
Cheapest isolate per gram
Bulk Pure Whey Isolate
2kg 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.
or compare all UK prices →Cheapest isolate per gram
Bulk Pure Whey Isolate
2kg bagPros
- + 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 · 24.3g protein in 30g▼
Protein makes up 81%
of this 30g scoop · 101 kcal total
Which casein is cheapest per gram?
Protein Works 100% Micellar Casein and Bulk Micellar Casein tie as the cheapest casein we checked, both at about 3.4p per gram of protein: Protein Works in its 4kg bag at £104.99, and Bulk in its 2.5kg bag at £67.99 on Amazon UK. Casein digests more slowly than whey, which is why people take it in the evening. Protein Works is the better buy if you will use 4kg, and Bulk if you want a smaller bag for the same price per gram.
Cheapest casein per gram
Protein Works 100% Micellar Casein Black
2kg bag
Protein powder from Protein Works. Compare prices across UK retailers.
or compare all UK prices →Cheapest casein per gram
Pros
- + Very high protein content
- + Slow release, great before bed
Cons
- – Premium price point
●Nutrition per scoop · 23.4g protein in 30g▼
Protein makes up 78%
of this 30g scoop · 107 kcal total
What is the cheapest vegan protein per gram?
Protein Works Vegan Soy Protein is the cheapest vegan protein per gram we checked: about 1.3p per gram in the 4kg Unflavoured bag (90g of protein per 100g) and 1.4p in Chocolate Silk (84g), both at £47.99. Soy is a complete protein, so it contains all the essential amino acids, and it scores well among plant proteins on protein quality (Herreman et al., 2020). Our best vegan protein powder guide covers taste and other options.
How can you pay less per gram of protein?
- Buy a bigger bag, up to a point. Moving from the smallest bag to about 1kg saves the most. Above 2kg the saving is often small. See our 1kg vs 2kg vs 5kg guide.
- Use codes that work for everyone. WW12 takes 12% off at Protein Works and WHEYWISE takes 10% off at Prozis. Other codes are on the deals page.
- Ignore price per kilo. A cheap bag with little protein in it can cost more per gram of protein than a dearer one. The WheyWise cheapest list does the maths for you.
Frequently asked questions
What is the cheapest protein per gram in the UK?
NutriSport 90+ in the 5kg bag on Amazon UK, at about 1.7p per gram of protein. It is a blend of whey, casein, soy and rice protein. The cheapest 100% whey we found is Applied Nutrition Critical Whey at about 3.8p per gram in the 2kg bag.
How do I compare protein powders by cost per gram of protein?
Multiply the bag weight in grams by the protein per 100g on the label, then divide by 100. That gives the grams of protein in the bag. Divide the price by that number to get the cost per gram. Multiply by 25 if you want the cost of a typical 25g shake.
Which whey protein brands offer the best price-to-protein ratio?
At normal prices, NutriSport 90+ (about 1.7p per gram), Bulk Basic Whey (2.6p) and Protein Works Whey Protein 360 Black (2.8p) give the most protein for your money. All three are blends that include soy. For 100% whey, Applied Nutrition Critical Whey (3.8p) and Bulk Pure Whey (4.2p) are the best value.
Is a bigger bag of protein always cheaper per gram?
Almost always, but the saving gets smaller as the bag gets bigger. Bulk Pure Whey costs about 5.6p per gram of protein in the 500g bag, 4.6p in 1kg and 4.2p in 5kg. Our pack size guide has the full numbers.
Is cost per gram of protein the same as price per kilo?
No. Price per kilo counts the whole powder, including carbs, fat and flavouring. Cost per gram of protein only counts the protein, so it is the fairer way to compare a high-protein powder with a cheaper, lower-protein one.
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