Protein Powder Price Per Serving: How to Compare Value Properly (UK)
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Why the tub price is the wrong number
Two tubs sitting next to each other at £30 and £40 tell you almost nothing about which is the better buy. Pack sizes run from 500g pouches to 5kg sacks. Scoop sizes differ from brand to brand. And the amount of protein in 100g of powder varies widely between products — it is printed on every label, but it is rarely the thing shoppers look at.
The fix is simple: convert everything to a common basis before you compare. There are three ways to do that, and they answer three different questions.
The three numbers that actually matter
1. Price per kilogram
The quickest sanity check. Divide the price by the pack weight in kilograms. It takes five seconds and immediately exposes the small-pack premium — the same product in a 500g pouch and a 2.27kg tub can sit at very different price-per-kg figures.
Its weakness: it treats every kilogram of powder as equivalent, and they aren't. A kilogram of a concentrate and a kilogram of an isolate contain different amounts of protein.
2. Price per serving
Divide the price by the number of servings in the pack. This is the number most people intuitively want, because it answers "what does one shake cost me?"
Watch two traps. First, brands set their own serving size, so a product with a small stated serving will look cheap per serving. Second, the "servings per container" figure on the front is usually rounded — work it out yourself: pack weight in grams ÷ serving size in grams.
3. Price per 25g of protein
This is the fairest comparison, because it strips out both pack size and serving size. Work out the total protein in the pack, then the price for each 25g of it:
- Protein per serving (g) × servings per pack = total protein in the pack (g)
- Total protein ÷ 25 = number of 25g units
- Price ÷ number of 25g units = price per 25g of protein
Use 25g because it is a round number, not because it is a recommendation. Any fixed reference amount works, as long as you apply the same one to every product you're comparing.
A worked example
The figures below are illustrative only — they are there to show the method, not to represent any real product or price. Always use the live figures on the product page.
| Tub A | Tub B | |
|---|---|---|
| Price | £30.00 | £40.00 |
| Pack weight | 1kg | 2.27kg |
| Serving size | 30g | 30g |
| Protein per serving | 24g | 21g |
| Servings per pack | 33 | 75 |
| Price per kg | £30.00 | £17.62 |
| Price per serving | £0.90 | £0.53 |
| Price per 25g protein | £0.94 | £0.63 |
Tub A is the "better" product on paper — 80% protein by weight against 70% — and it still loses on every value measure. Protein percentage on its own never decides value; it only matters once you put it against the price.
Where to find the numbers on the label
- Serving size and servings per container — top of the nutrition panel, usually stated in grams and in scoops.
- Per 100g column — the only column that is directly comparable between brands, because it is independent of scoop size.
- Per serving column — what you'll use for the per-serving maths.
- Ingredient list — in descending order of weight, so the first named ingredient is the largest by weight.
- %NRV — where vitamins or minerals are added, the percentage of the EU/UK Nutrient Reference Value per serving, so you can compare like with like across products.
- Best before date and batch number — on the base or the seal. Worth checking on discounted stock.
One habit worth forming: never compare "per scoop". Scoops are not a standard size and two brands can differ by 10g or more.
Comparing formats on the same basis
Powder is almost always the cheapest way to buy protein per gram, but it isn't always the format that suits the buyer. Run the same arithmetic across formats before deciding.
| Format | Compare on | Practical notes |
|---|---|---|
| Powder (tub or pouch) | Price per 25g protein | Cheapest per gram; needs a shaker, water and somewhere to store the tub |
| Ready-to-drink | Price per bottle and per 25g protein | No preparation, fixed portion, heavy to carry, higher cost per gram |
| Bars and snacks | Price per bar and per 25g protein | Travel and desk-drawer convenience; priced as a snack, not as bulk powder |
| Multipacks and bundles | Price per unit after the discount | Only cheaper if you'd have bought all the units anyway |
You can run these comparisons across our protein powders, ready-to-drink and protein bars and snacks ranges.
Costs that don't appear on the price tag
- Delivery. A cheap 1kg tub plus postage can cost more than a larger tub that clears the free-delivery threshold. Check the current threshold at checkout and add delivery into your per-serving figure.
- Flavour risk. The most common way to waste money is buying 2.27kg of a flavour you turn out to dislike. If you haven't tried it, buy the small size first, then scale up.
- Shelf life. Big tubs take longer to get through. Check the best-before date against how fast you'll realistically use it — particularly on sale and clearance lines.
- Storage. Keep the pack sealed, cool and dry, and keep the scoop dry. Damp powder clumps and gets thrown away, which is money wasted.
- Mixability. A practical, taste-and-texture matter rather than anything else — some powders shake out smoothly in water, others are better in a blender. Reviews are more useful here than the label.
Certification: what Informed Sport and Informed Choice mean
Both are banned-substance testing programmes run by LGC. Certified products carry a logo and appear in a searchable online database.
- Informed Sport — every batch is screened against LGC's list of substances prohibited in sport before it is released for sale. You can look up the individual batch number from your tub in the programme's database.
- Informed Choice — products are sampled blind from retail on a monthly basis rather than batch by batch.
Certification is a screening programme, not a statement about quality, taste or value, and certified lines typically carry a higher price per kilogram to cover the testing. If you compete under anti-doping rules, that premium is the point. If you don't, it's simply a cost to weigh up like any other — the same logic applies across categories such as creatine.
The short version
- Ignore the headline tub price.
- Work out price per kilogram as a fast filter.
- Work out price per serving and price per 25g of protein for a real comparison.
- Read the per-100g column, not the scoop.
- Add delivery in before you decide.
- Try a small pack of an unfamiliar flavour before committing to a large one.
- Only pay a certification premium if you actually need certification.
Two minutes with a calculator is usually worth more than an hour of comparing tub prices, and the numbers you need are all printed on the label.