About this site
One number, computed honestly, across every 3D printing consumable we can find on Amazon UK.
3D printing has a pricing problem that storage and memory solved years ago: nobody shows you the unit price. Filament is sold in 250 g mini spools, 1 kg standards, 2.2 kg bundles and 5 kg multipacks, at prices that only make sense once you divide. A "40% off" badge on an overpriced spool beats a cheaper spool at full price in every listing Amazon shows you, and loses on the only measure that matters.
So this site does the division. Every filament listing we track is ranked by cost per kilogram, every resin by cost per litre, with bundles counted at their total weight so a four-pack competes fairly with a single roll.
Where the data comes from
Prices, price history and discount figures come from the Keepa API, which tracks Amazon pricing over time. Weights, materials and pack counts are parsed from the product titles themselves. Where a title does not state a usable weight, we leave the per-kilo figure blank rather than guess — a confidently wrong ranking is worse than an honest gap.
What we do not do
We do not accept payment for placement, and the ranking is computed from price and weight alone. We hold no stock, take no orders and handle no payments; every purchase happens on Amazon.