Method
How Baglist turns a measurement into a shopping count.
Every calculator on Baglist uses the same three ideas.
The geometry is fixed. A rectangle’s volume is length times width times thickness, and its area is length times width. Millimetres are divided by 1000 so the rest of the sum is in metres. Litres are cubic metres times 1000. Mass is volume times the loose density printed on that page.
The pack is a preset, not a law. Bag yield, tin size, board width and tiles per square metre are numbers you can change. Each calculator’s Checked line names the listing looked at on 10 November 2026, and it says so when a figure is still an assumption. The geometry does not depend on that check.
The shopping count rounds up. Waste, where a page uses it, is applied to the measured quantity first: quantity times one plus the waste percentage. That result is divided by the amount in one bag, tin, sheet or tile, and anything left over rounds up to a whole pack. An exact division does not add an extra pack. The page shows the unrounded figure beside the count.
The measurement stays in this browser. Nothing on the page sends the length, width or thickness to a server. The only thing stored on the device is the market, UK or Australia, under the name baglist-market.
The two markets exist because the packs differ. A 20 kg bag in Australia is not the same assumption as a 25 kg bag in Britain, and a fence bay is not the same width. Switching market changes those presets and leaves the size you typed.
None of this is structural, safety or planning advice. It is a shopping list. Read the bag or the datasheet before you buy, and for a fence in England read the planning guidance linked on that page.