Skirting and coving calculator

How much skirting, coving or architrave a room needs, with a cut list against the lengths it's sold in.

Sets the lengths it's sold in and the usual door size.

Trim
Measure by
Lengths to buy

As sold mixes the lengths shops usually stock in your region.

Extra for offcuts, spills, breakages and mistakes.

More options

You'll need

Skirting

14.56 m

Buy 4 lengths of 4.2 m (16.8 m)

Includes 10% for waste.

Cut list

  • 1 × 4.2 m: cut 4 m, offcut 0.2 m
  • 1 × 4.2 m: cut 3.24 m, offcut 0.96 m
  • 2 × 4.2 m: cut 3 m, offcut 1.2 m
How it's worked out
  1. Round the room: 2 × (4 m + 3 m) = 14 m
  2. 14 m − 1 door × 0.76 m = 13.24 m, the doors taken off the longest walls
  3. 13.24 m + 10% for waste = 14.56 m
  4. Skirting is usually sold in 2.4 m and 4.2 m
  5. Buy 4 lengths of 4.2 m = 16.8 m

Estimates only — verify before purchase. Check the quantities against your own measurements and the product's label.

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What it works out

This works out how much skirting, coving or architrave a room needs, and how to cut it from the lengths shops sell. It gives the total length with waste, the lengths to buy, and a cut list saying which pieces come from which length.

It's for decorative trim: skirting boards along the bottom of the walls, coving where the walls meet the ceiling, and architrave round door frames.

How it works

For skirting and coving, give the room's length and width, or each wall's length. The calculator adds up the perimeter. Skirting stops at each door, so each door's width comes off the longest wall left; coving runs round the whole room.

Architrave is worked out per door: two legs up the sides and a head across the top, each a little longer than the opening so the corners can be mitred, on one side of the door or both.

It then plans the cuts. Each wall is a piece to cut, longest first, from the lengths your region's shops stock or one length you type in. A wall longer than the longest length is cut in two and joined. Spare lengths are added until what you buy covers the total plus the waste allowance.

A worked example

Skirting for a room 4 m by 3 m with 1 door, each 0.76 m wide, cut from the lengths shops usually sell.

  1. Round the room: 2 × (4 m + 3 m) = 14 m
  2. 14 m − 1 door × 0.76 m = 13.24 m, the doors taken off the longest walls
  3. 13.24 m + 10% for waste = 14.56 m
  4. Skirting is usually sold in 2.4 m and 4.2 m
  5. Buy 4 lengths of 4.2 m = 16.8 m

The result

  • Skirting14.56 mBuy 4 lengths of 4.2 m (16.8 m)

These are the calculator's own figures for these measurements, with 10% for waste. Change any of them above and it works it out again.

Common mistakes

  • Buying the total length in short pieces. A wall longer than your stock length needs a joint. Fewer, longer lengths mean fewer joints on show.
  • Forgetting the mitres. Every internal and external corner is cut at an angle, and each one eats a little length. That's what the waste allowance is for.
  • Counting doors for coving. Coving runs over the doors, so it needs the full perimeter. Skirting doesn't.
  • Cutting before checking the walls. Old walls are rarely straight or square. Measure each wall where the trim will go, not across the middle of the room.

Questions people ask

How much skirting board do I need?

Measure round the room, take off the width of each doorway, and add a margin for cuts and mitres. The calculator does that and tells you which lengths to buy.

What lengths does skirting come in?

It depends on the shop and the country. The calculator uses the lengths shops in your region usually stock, mixed to suit your walls, or one length you type in.

How is architrave measured?

Per door: two legs up the sides and a head across the top, each a little longer than the opening to allow for the mitred corners. Most doors have architrave on both sides.

What do I do with a wall longer than my lengths?

Cut it from two pieces and join them, ideally with a scarf joint over a fixing point. The cut list shows where that happens.

Should I leave a gap for the flooring?

Skirting usually sits on the floor finish, or covers the expansion gap a floating floor needs. Fit the flooring first where you can.