Cost Per Gram of Protein · 2026
Cheapest Protein Powder Per Gram UK 2026
Price per tub tells you almost nothing. A big cheap tub can cost more per gram of protein than a smaller premium one. We rank every UK protein powder by the metric that actually matters: the true cost of one gram of protein.
For each product we work out the grams of protein per serving, multiply by the servings in the tub, and divide the price by the total protein. Every powder also carries its Effectiveness Match score, so you can see whether the cheapest per gram is also well formulated. Rankings recalculate as prices change.
Cheapest Per Gram
The lowest cost-per-gram-of-protein picks across whey, isolate and casein.
Whey
Ranked by cost per gram of protein
Whey Isolate
Ranked by cost per gram of protein
Casein
Ranked by cost per gram of protein
How cost per gram is worked out
Protein per serving is the serving size multiplied by the protein content by weight. Multiply that by the servings in the tub for the total grams of protein, then divide the price by that total. The result is the real price of one gram of protein, the fairest way to compare powders of different sizes and protein percentages. A whey concentrate is usually cheapest per gram; a whey isolate costs a little more but is leaner and lower in lactose.
Informational only — not medical advice. Buy links are affiliate links; we may earn a commission at no extra cost to you. This never affects scoring or rankings.