Coving Length Calculator

About this calculator

Coving (also called cornice) is the decorative moulding installed along the join between wall and ceiling, and calculating how much you need is simply the room's total perimeter — the sum of all four wall lengths — divided by the standard length of a single coving piece (commonly sold in 2m or 3m lengths), rounded up and then adjusted for the number of pieces per pack the supplier sells.

Decorators and DIY homeowners calculate this before ordering coving because miscalculating the perimeter or forgetting to round up for waste at internal and external corners (where pieces need to be mitred and off-cuts can't always be reused) is one of the most common reasons a job gets held up waiting for an extra pack to arrive mid-installation.

This calculator takes your room's dimensions and the coving length per piece and pieces per pack, and returns the total metres of coving you need and exactly how many packs to buy.