What is the cheapest whey protein in the UK?

Bulk Diet Whey Protein, £31.98 per kilo. Today's lowest price for whey protein across the shops we track, £0.97 per kilo less than number two.

Bulk Diet Whey Protein
Cheapest per kilo £31.98 per kilo Bulk Diet Whey Protein 500 g for £15.99 · £0.96 per serving
View at Bulk £15.99

Measured 8 October · 372 whey powders at 4 shops · updated every day

How we calculate

  • Price per kilo. A small bag looks cheap. Per kilo shows what you really pay.
  • Discount included. The price is what you pay at checkout, with our code already applied.

The lowest price per kilo is at the top. That spot is not for sale. If you order through us, the shop pays us a commission. That doesn't change the order.

Which whey protein is the cheapest per kilo right now?

price per kilo, discount included
  1. 1 Bulk Diet Whey Protein 500 g for £15.99 £31.98 per kilo View
  2. 2 Applied Nutrition Diet Whey Protein Isolate 1 kg for £32.95 £32.95 per kilo View
  3. 3 Myprotein Impact Whey Protein Powder 1 kg for £32.99 £32.99 per kilo View
  4. 4 Optimum Nutrition Gold Standard 100% Isolate Whey Protein 930 g for £58.00 £62.37 per kilo View
Compare all protein →

What should you look for?

  • Protein per serving. A slightly dearer whey with more protein can be cheaper per gram of protein.
  • Flavour and sweeteners. Check whether you like the flavour and whether it uses artificial sweeteners.
  • Bag size. Big bags push the price per kilo down. The list already works per kilo.

Questions

All whey prices side by side (per kilo)
# Product Price Price per unit Rating Last measured
1 Bulk Diet Whey Protein · 3 flavours £15.99 · 500 g £31.98 / kg —
2 Applied Nutrition Diet Whey Protein Isolate · 60 flavours £32.95 · 1 kg £32.95 / kg —
3 Myprotein Impact Whey Protein Powder · 254 flavours £32.99 (-6%) · 1 kg £32.99 / kg 4,6/5 (29585)
4 Optimum Nutrition Gold Standard 100% Isolate Whey Protein · 61 flavours £58.00 · 930 g £62.37 / kg 4,9/5 (328)

Prices checked on 9 October 2026 — discounts are already included in the price per unit.

What does a whey shake cost per day and per month?

Count on one shake of 30 grams a day: that shows what the price difference per kilo means for your wallet.

Product Per shake (30 g) Per month
Bulk Diet Whey Protein £31.98 per kilo £0.96 £28.78
Applied Nutrition Diet Whey Protein Isolate £32.95 per kilo £0.99 £29.66
Myprotein Impact Whey Protein Powder £32.99 per kilo £0.99 £29.69
Optimum Nutrition Gold Standard 100% Isolate Whey Protein £62.37 per kilo £1.87 £56.13

Calculated from the price per kilo (discount included) × 30 grams per shake, 30 times a month. Prices checked on 9 October 2026.

What is the cheapest whey protein in the UK?
The lowest price for whey protein across the shops we track is today Bulk Diet Whey Protein: £31.98 per kilo (£15.99 per bag of 500 g, discount included). Measured on 8 October across 372 whey powders at 4 shops; powder only. That changes every week: the list above is live and re-sorts itself automatically.
What exactly is whey protein?
Whey is the protein left over when cheese is made. It is filtered and dried into a powder and contains all the essential amino acids. Because the body absorbs it quickly, it is especially popular after training.
Is cheap whey as good as expensive whey?
Often, yes. Most whey concentrates sit close together in protein content. Look mainly at the protein per serving and the flavour; the brand matters less than you think. How we rate products: the SupplementScore.
Whey concentrate or isolate?
Isolate is filtered further, has a bit more protein and less lactose and fat. It is usually dearer. For most people concentrate is enough. The lowest price per kilo for isolate: the cheapest whey isolate.
Which protein shake with a lactose intolerance?
Take a whey isolate or a clear whey: the extra filtering leaves hardly any lactose. With a full lactose intolerance a plant protein from soy or pea is the safest choice. The prices: the cheapest clear whey.
How much whey do you need a day?
One or two shakes a day is usual, depending on how much protein you already get from food. Guideline: 1.6 to 2 grams of protein per kilo of body weight a day.
Full explanation

Whey is the most popular protein powder for building muscle, but the price differs a lot from brand to brand. We compare the whey proteins of all the shops we track by price per kilo, discounts and our code SPORTPOEDER already included. So you see at a glance where you buy cheapest. Struggle with lactose? Then look at a whey isolate or a clear whey: both are filtered further and contain hardly any milk sugar.

Where does the price difference between whey types come from?

Do not look at the price per kilo alone: a slightly dearer whey with more protein can still be cheaper per gram of protein.

TypeWhat you getWhen the extra is worth it
Whey concentrateMost concentrates sit close together in protein content; the cheapest per kilo.Almost always: for most people concentrate is the right choice.
Whey isolateFiltered further: a bit more protein, hardly any lactose and fat. Usually dearer.If you struggle with lactose or every gram of protein has to count.
Clear wheyThe same filtering as isolate, but it drinks like a squash instead of a milkshake.If a thick shake is too much for you.
Plant-based (soy/pea)Dairy-free alternative without lactose.With a full lactose intolerance or a vegan diet.

Not choosing on price alone? How the SupplementScore works →

Independently compared · how we calculate · open data feed (JSON)

Bulk · 500 g £15.99
View at Bulk