Paint in litres and flooring in square metres
For paint, measure the wall area, deduct openings and use the coverage per coat printed on the tin. Add the ceiling only when required. A litre estimate and the number of whole tins are separate results.
For flooring, copy the coverage per pack in m². A 20 m² room with a chosen 10% allowance needs 22 m² before rounding. Packs covering 1.8 m² require 13 packs, giving 23.4 m² to purchase.
Curtain drop, fullness and fabric width
UK curtain guides may show centimetres and inches together. Measure the fitted pole or track and the drop from the appropriate hanging point. Keep all inputs in the displayed unit; a ready-made curtain's finished size is different from fabric cut length.
For sewing, include the heading allowance, hem and pattern repeat. Check whether the quoted width is per curtain or per pair. Use the fabric's usable width when counting joined widths, and enter the price per metre or yard shown beside the price field.
Compost bags: calculate the filled space
Measure inside the container to the intended compost level, leaving any planned watering space above it. Subtract the root-ball volume before adding an allowance. In a tapered pot, take the upper diameter at the fill level rather than the rim.
Compare the result in litres with the bag's stated volume. For example, 50 × 20 × 20 cm gives 20 L before subtracting roots. Enter your current bag price to estimate material cost; delivery and planting supplies need separate entries in your budget.
Frequently asked questions
Does imperial mode use British gallons?
No. Fields labelled US gal use US liquid gallons. For paint or compost sold in litres, metric mode avoids mixing US and British imperial gallon sizes.
Can I use ready-made curtain measurements?
They help establish the finished width and drop. The fabric calculator also needs sewing allowances and fabric width; it does not select a ready-made curtain size.